Solid-state image sensor

ABSTRACT

A solid-state image sensor includes a plurality of imaging element blocks each configured from a plurality of imaging elements. Each of the imaging elements includes a first electrode, a charge accumulating electrode arranged in a spaced relation from the first electrode, a photoelectric conversion portion contacting with the first electrode and formed above the charge accumulating electrode with an insulating layer interposed therebetween, and a second electrode formed on the photoelectric conversion portion. The first electrode and the charge accumulating electrode are provided on an interlayer insulating layer, and the first electrode is connected to a connection portion provided in the interlayer insulating layer.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a national stage application under 35 U.S.C. 371 andclaims the benefit of PCT Application No. PCT/JP2019/027890 having aninternational filing date of 16 Jul. 2019, which designated the UnitedStates, which PCT application claimed the benefit of Japanese PatentApplication No. 2018-140218, filed 26 Jul. 2018, the entire disclosuresof each of which are incorporated herein by reference.

TECHNICAL FIELD

The present disclosure relates to a solid-state image sensor.

BACKGROUND ART

An imaging element in which an organic semiconductor material is usedfor a photoelectric conversion layer can perform photoelectricconversion of a specific color (wavelength band). Further, since theimaging element has such a feature as just described, in a case where itis used as an imaging element in a solid-state image sensor, it ispossible to obtain a structure (stacked type imaging element) in which asubpixel is configured from a combination of an on-chip color filter(OCCF) and the imaging element, such subpixels being arrayedtwo-dimensionally, and with which stacking of the subpixels that cannotbe implemented by a conventional solid-state image sensor is implemented(for example, refer to PTL 1). Further, the imaging elements isadvantageous in that, since a demosaic process is not demanded, a falsecolor does not appear. It is to be noted that, in the followingdescription, an imaging element including a photoelectric conversionportion provided on or above a semiconductor substrate is sometimesreferred to as “first type imaging element” for the convenience ofdescription, a photoelectric conversion portion configuring the firsttype imaging element is sometimes referred to as “first typephotoelectric conversion portion” for the convenience of description, animaging element provided in a semiconductor substrate is sometimesreferred to as “second type imaging element” for the convenience ofdescription, and a photoelectric conversion portion configuring thesecond type imaging element is sometimes referred to as “second typephotoelectric conversion portion” for the convenience of description.

An example of a structure of a stacked type imaging element (stackedtype solid-state image sensor) disclosed in PTL 1 is depicted in FIG. 9. In the example depicted in FIG. 9 , the imaging element is formed bystacking, in a semiconductor substrate 70, a third photoelectricconversion portion 43 and a second photoelectric conversion portion 41that are second type photoelectric conversion portions configuring athird imaging element 15 and a second imaging element 13 that are secondtype imaging elements. Further, a first type photoelectric conversionportion configuring the first imaging element (referred to as “firstphotoelectric conversion portion” for the convenience of description) isarranged above the semiconductor substrate 70 (particularly, above thesecond imaging element 13). Here, the first photoelectric conversionportion includes a first electrode 21, a photoelectric conversionportion 23 formed from an organic material, and a second electrode 22,and configures a first imaging element 11 that is a first type imagingelement. Further, a charge accumulating electrode 24 is provided in aspaced relation from the first electrode 21, and a photoelectricconversion portion 23 is positioned above the charge accumulatingelectrode 24 with an insulating layer 82 interposed therebetween. In thesecond photoelectric conversion portion 41 and the third photoelectricconversion portion 43, for example, blue light and red light arephotoelectrically converted depending upon the difference in absorptioncoefficient. Further, in the first photoelectric conversion portion, forexample, green light is photoelectrically converted.

Charge generated by photoelectric conversion in the second photoelectricconversion portion 41 and the third photoelectric conversion portion 43is accumulated into the second photoelectric conversion portion 41 andthird photoelectric conversion portion 43 once, and then is transferredto a second floating diffusion layer (Floating Diffusion) FD₂ and athird floating diffusion layer FD₃ by a vertical type transistor (whosegate portion 45 is depicted) and a transfer transistor (whose gateportion 46 is depicted). Further, the generated charge is outputted toan external reading out circuit (not depicted). The transistors andfloating diffusion layers FD₂ and FD₃ are also formed on thesemiconductor substrate 70.

Charge generated by photoelectric conversion in the first photoelectricconversion portion is attracted to the charge accumulating electrode 24upon charge accumulation and is accumulated into the photoelectricconversion portion 23. Upon charge transfer, the charge accumulated inthe photoelectric conversion portion 23 is accumulated into the firstfloating diffusion layer FD₁ formed on the semiconductor substrate 70through the first electrode 21, a contact hole portion 61, and a wiringlayer 62. Further, the first photoelectric conversion portion isconnected also to a gate portion 52 of an amplification transistor forconverting a charge amount into a voltage through the contact holeportion 61 and the wiring layer 62. Further, the first floatingdiffusion layer FD₁ configures part of a reset transistor (whose gateportion 51 is depicted). It is to be noted that the other components aredescribed in connection with an embodiment 1.

CITATION LIST Patent Literature

[PTL 1]

Japanese Patent Laid-Open No. 2017-157816

SUMMARY Technical Problems

Although hereinafter described in detail, such a first problem occursthat, depending upon the angle of light incident to the first imagingelement 11, a difference appears in movement state of charge generatedin the photoelectric conversion portion 23 of each first imaging element11 to the first electrode 21 between first imaging elements 11 adjacentto each other and, as a result, there is the possibility that picturequality may degrade in an obtained image. Further, such a second problemoccurs that it is not considered that there is no possibility that,during operation of the first imaging element 11, charge accumulated inthe photoelectric conversion portion 23 may move to the adjacent firstimaging element 11 and that it is not considered that there is nopossibility that charge accumulated in the photoelectric conversionportion 23 may not be transferred smoothly to the first electrode 21.This gives rise to a result of characteristic degradation of thesolid-state image sensor.

Accordingly, it is a first object of the present disclosure to provide asolid-state image sensor in which a difference does not occur inmovement state of charge generated in an imaging element to a firstelectrode depending upon the angle of light incident to the imagingelement. Further, it is a second object of the present disclosure toprovide a solid-state image sensor that includes an imaging elementhaving a configuration and a structure by which movement of chargebetween imaging elements adjacent to each other can be suppressed withcertainty during operation of the imaging elements and chargeaccumulated in a photoelectric conversion portion is transferredsmoothly to a first electrode.

Solution to Problems

In order to attain the first object described above, a solid-state imagesensor of the present disclosure includes a plurality of imaging elementblocks each configured from a plurality of imaging elements. Each of theimaging elements includes a first electrode, a charge accumulatingelectrode arranged in a spaced relation from the first electrode, aphotoelectric conversion portion contacting with the first electrode andformed above the charge accumulating electrode with an insulating layerinterposed therebetween, and a second electrode formed on thephotoelectric conversion portion. The first electrode and the chargeaccumulating electrode are provided on an interlayer insulating layer.The first electrode is connected to a connection portion provided in theinterlayer insulating layer.

BRIEF DESCRIPTION OF DRAWINGS

FIGS. 1A and 1B are views schematically depicting an arrangement stateof a charge accumulating electrode, a first electrode, and so forth in asolid-state image sensor of an embodiment 1 and a solid-state imagesensor of an embodiment 2, respectively.

FIGS. 2A and 2B are views schematically depicting an arrangement stateof a charge accumulating electrode, a first electrode, an isolationelectrode, and so forth in a modification of the solid-state imagesensor of the embodiment 2.

FIGS. 3A and 3B are views schematically depicting an arrangement stateof a charge accumulating electrode, a first electrode, and so forth in asolid-state image sensor of an embodiment 3 and a modification of theembodiment 3, respectively.

FIGS. 4A and 4B are views schematically depicting an arrangement stateof a charge accumulating electrode, a first electrode, an isolationelectrode, and so forth in a modification of the solid-state imagesensor of the embodiment 3.

FIGS. 5A and 5B are views schematically depicting an arrangement stateof a charge accumulating electrode, a first electrode, and so forth in asolid-state image sensor of an embodiment 4 and a modification of theembodiment 4, respectively.

FIGS. 6A and 6B are views schematically depicting an arrangement stateof a charge accumulating electrode, a first electrode, an isolationelectrode, and so forth in a modification of the solid-state imagesensor of the embodiment 4.

FIGS. 7A and 7B are views schematically depicting an arrangement stateof a charge accumulating electrode, a first electrode, and so forth in amodification of the solid-state image sensor of the embodiment 4.

FIGS. 8A and 8B depict a schematic perspective view of the modificationof the solid-state image sensor of the embodiment 4 depicted in FIG. 6Aand a schematic perspective view of a modification of a conventionalsolid-state image sensor, respectively.

FIG. 9 is a schematic partial sectional view of the solid-state imagesensor of the embodiment 1.

FIGS. 10A and 10B are schematic sectional views of part of imagingelements (two imaging elements arranged side by side) configuring thesolid-state image sensor of the embodiment 1 and the modification of theembodiment 1.

FIG. 11 is an equivalent circuit diagram of the imaging element and astacked type imaging element of the embodiment 1.

FIG. 12 is an equivalent circuit diagram of the imaging element and thestacked type imaging element of the embodiment 1.

FIG. 13 is a schematic arrangement diagram of the first electrode andthe charge accumulating electrode and transistors configuring a controlportion that configure the imaging element of the embodiment 1.

FIG. 14 is a view schematically depicting a state of a potential at eachportion upon operation of the imaging element of the embodiment 1.

FIGS. 15A and 15B are equivalent circuit diagrams of the imaging elementand the stacked type imaging element of the embodiment 1 and anembodiment 8 for illustrating portions of FIG. 14 (embodiment 1) andFIGS. 32 and 33 (embodiment 8).

FIG. 16 is a conceptual diagram of the solid-state image sensor of theembodiment 1.

FIG. 17 is an equivalent circuit diagram of a modification of theimaging element and the stacked type imaging element of the embodiment1.

FIG. 18 is a schematic arrangement diagram of the first electrode andthe charge accumulating electrode and transistors configuring thecontrol portion that configure another modification of the imagingelement of the embodiment 1 depicted in FIG. 17 .

FIGS. 19A and 19B are schematic sectional views of part of the imagingelements (two imaging elements arranged side by side) configuring thesolid-state image sensor of the embodiment 2 and a modification of theembodiment 2.

FIG. 20 is a schematic sectional view of part of the imaging elements(two imaging elements arranged side by side) of the embodiment 5.

FIGS. 21A and 21B are schematic sectional views of part of amodification of the imaging elements (two imaging elements arranged sideby side) of the embodiment 5.

FIGS. 22A and 22B are schematic sectional views of part of amodification of the imaging elements (two imaging elements arranged sideby side) of the embodiment 5.

FIG. 23 is a schematic partial sectional view of a solid-state imagesensor of an embodiment 6.

FIG. 24 is a schematic partial sectional view of a solid-state imagesensor of an embodiment 7.

FIG. 25 is a schematic partial sectional view of a modification of thesolid-state image sensor of the embodiment 7.

FIG. 26 is a schematic partial sectional view of another modification ofthe imaging element of the embodiment 7.

FIG. 27 is a schematic partial sectional view of still anothermodification of the imaging element of the embodiment 7.

FIG. 28 is a schematic partial sectional view of part of a solid-stateimage sensor of an embodiment 8.

FIG. 29 is an equivalent circuit diagram of the solid-state image sensorof the embodiment 8.

FIG. 30 is an equivalent circuit diagram of the solid-state image sensorof the embodiment 8.

FIG. 31 is a schematic arrangement diagram of a first electrode, atransfer controlling electrode, and a charge accumulating electrode andtransistors configuring a control portion that configure the imagingelement of the embodiment 8.

FIG. 32 is a view schematically depicting a state of a potential at eachportion upon operation of the imaging element of the embodiment 8.

FIG. 33 is a view schematically depicting a state of a potential at eachportion upon different operation of the imaging element of theembodiment 8.

FIG. 34 is a schematic arrangement diagram of a first electrode, atransfer controlling electrode, and a charge accumulating electrode andtransistors configuring the control portion that configure amodification of the imaging element of the embodiment 8.

FIG. 35 is a schematic partial sectional view of a solid-state imagesensor of an embodiment 9.

FIG. 36 is a schematic partial sectional view of still anothermodification of the solid-state image sensor of the embodiment 1.

FIG. 37 is a schematic partial sectional view of yet anothermodification of the solid-state image sensor of the embodiment 1.

FIG. 38 is a schematic partial sectional view of a further modificationof the solid-state image sensor of the embodiment 1.

FIG. 39 is a schematic partial sectional view of a still furthermodification of the solid-state image sensor of the embodiment 1.

FIG. 40 is a schematic partial sectional view of a yet furthermodification of the solid-state image sensor of the embodiment 1.

FIG. 41 is a conceptual diagram of an example in which a solid-stateimage sensor configured from the solid-state image sensor of the presentdisclosure is used in electronic equipment (camera).

FIG. 42 is a conceptual diagram of part of the solid-state image sensorfor illustrating a driving method for an example of the solid-stateimage sensor of the present disclosure.

FIG. 43 is a view schematically depicting an arrangement state of afirst electrode and so forth of a conventional solid-state image sensorfor illustrating a first problem.

FIG. 44 is a block diagram depicting an example of schematicconfiguration of a vehicle control system.

FIG. 45 is a diagram of assistance in explaining an example ofinstallation positions of an outside-vehicle information detectingsection and an imaging section.

FIG. 46 is a view depicting an example of a schematic configuration ofan endoscopic surgery system.

FIG. 47 is a block diagram depicting an example of a functionalconfiguration of a camera head and a camera control unit (CCU).

DESCRIPTION OF EMBODIMENTS

In the following, the present disclosure is described on the basis ofembodiments with reference to the drawings. However, the presentdisclosure is not limited to the embodiments and various values andmaterials in the embodiments are exemplary. It is to be noted that thedescription is given in the following order.

1. Description of Solid-State Image Sensor in General of PresentDisclosure

2. Embodiment 1 (Solid-State Image Sensor of Present Disclosure andSolid-State Image Sensor of First Configuration)

3. Embodiment 2 (Modification to Embodiment 1)

4. Embodiment 3 (Modification of Embodiment 1 and Embodiment 2 andSolid-State Image Sensor of Second Configuration)

5. Embodiment 4 (Another Modification of Embodiment 1 and Embodiment 2and Solid-State Image Sensor of Third Configuration)

6. Embodiment 5 (Modification of Embodiment 1 to Embodiment 4 and UpperIsolation Electrode)

7. Embodiment 6 (Modification of Embodiment 1 to Embodiment 5 andFront-Illuminated Type Solid-State Image Sensor)

8. Embodiment 7 (Modification of Embodiment 1 to Embodiment 6)

9. Embodiment 8 (Embodiment 1 to Embodiment 7 and Transfer ControllingElectrode)

10. Embodiment 9 (Embodiment 1 to Embodiment 8 and Charge DischargingElectrode)

11. Others

<Description of Solid-State Image Sensor in General of PresentDisclosure>

The solid-state image sensor of the present disclosure can be formedsuch that a imaging element block is configured from P×Q (where, P≥2 andQ≥1) imaging elements including P imaging elements along a firstdirection and Q imaging elements along a second direction different fromthe first direction.

The above-described preferred form of the solid-state image sensor ofthe present disclosure can be configured such that, in order to attainthe second object described above, P=2 and Q=1 are satisfied, and thefirst electrodes individually configuring two imaging elements along thefirst direction are connected to a connection portion provided in theinterlayer insulating layer. Here, the solid-state image sensor havingsuch a configuration as just described is referred to “solid-state imagesensor of the first configuration” for the convenience of description.In the two imaging elements, the first electrodes are connected to eachother through the connection portion. Further, the solid-state imagesensor of the first configuration can be configured such that theimaging element block is surrounded by a continuous isolation electrode(sometimes referred to as “first isolation electrode” for theconvenience of description) and can be further configured such that acontinuous second isolation electrode extending along the seconddirection from the isolation electrode (first isolation electrode) isprovided between the two imaging elements along the first direction. Thefirst isolation electrode and the second isolation electrode areconnected to each other. Alternatively, the solid-state image sensor ofthe first configuration can be configured such that a second isolationelectrode extending along the second direction is provided between thetwo imaging elements along the first direction.

Alternatively, in order to attain the second object described above, thepreferred form described above of the solid-state image sensor of thepresent disclosure can be configured such that P=2 is satisfied and Q isa natural number equal to or greater than 2, and the first electrodesindividually configuring the two imaging elements along the firstdirection are connected to a connection portion provided in theinterlayer insulating layer. Here, a solid-state image sensor havingsuch a configuration as just described is referred to as “solid-stateimage sensor of the second configuration” for the convenience ofdescription. In the P×Q imaging elements, the first electrodes areconnected to each other through the connection portion. Further, thesolid-state image sensor of the second configuration can be configuredsuch that the imaging element block is surrounded by a continuousisolation electrode (first isolation electrode) and can be furtherconfigured such that a continuous second isolation electrode extendingalong the second direction from the isolation electrode (first isolationelectrode) is provided between the two imaging elements along the firstdirection. The first isolation electrode and the second isolationelectrode are connected to each other. Alternatively, the solid-stateimage sensor of the second configuration can be configured such that asecond isolation electrode extending along the second direction isprovided between the two imaging elements along the first direction.

Alternatively, in order to attain the second object described above, thepreferred mode described above of the solid-state image sensor of thepresent disclosure can be configured such that P=2 and Q=2 aresatisfied, the first electrode configuring the two imaging elementsalong the second direction is shared, and the shared first electrode isconnected to a connection portion provided in the interlayer insulatinglayer. Here, the solid-state image sensor having such a configuration asjust described is referred to as “solid-state image sensor of the 3Athconfiguration” for the convenience of description. Alternatively, inorder to attain the second object described above, the preferred modedescribed above of the solid-state image sensor of the presentdisclosure can be configured such that P=2 and Q=2 are satisfied, thefirst electrode configuring the two imaging elements along the firstdirection is shared, and the shared first electrode is connected to aconnection portion provided in the interlayer insulating layer. Here,the solid-state image sensor having such a configuration as justdescribed is referred to as “solid-state image sensor of the 3Bthconfiguration” for the convenience of description. In the 2×2 imagingelements, the first electrodes are connected to each other through theconnection portion. Then, the solid-state image sensor of the 3Athconfiguration or the solid-state image sensor of the 3Bth configurationcan be configured such that the imaging element block is surrounded by acontinuous isolation electrode (first isolation electrode). Further, thesolid-state image sensor of the 3Ath configuration or the solid-stateimage sensor of the 3Bth configuration can be configured such that acontinuous second isolation electrode extending along the seconddirection from the isolation electrode (first isolation electrode) isprovided between the two imaging elements along the first direction. Thefirst isolation electrode and the second isolation electrode areconnected to each other. Alternatively, the solid-state image sensor ofthe 3Ath configuration or the solid-state image sensor of the 3Bthconfiguration can be configured such that a second isolation electrodeextending along the second direction is provided between the two imagingelements along the first direction.

Further, the solid-state image sensor of the present disclosureincluding the preferred forms and configurations described above can beformed such that the imaging elements are arranged line-symmetricallywith respect to a boundary line extending in the second directionbetween the imaging elements configuring the imaging element block.

Furthermore, the solid-state image sensor of the present disclosureincluding the preferred forms and configurations described above can beformed such that the potential of the isolation electrode (firstisolation electrode) (in a case where the second isolation electrode isprovided, the potential of the second isolation electrode also) has afixed value V_(ES).

If the first electrode is shared in the P×Q imaging elements configuringone imaging element block in this manner, then the configuration and thestructure in a pixel region in which a plurality of imaging elements isarrayed can be simplified and refined. Further, the solid-state imagesensor can be formed such that the plurality of (particularly, P×Q)imaging elements configuring the imaging element block includes a sharedfloating diffusion layer. In other words, one floating diffusion layeris provided for one imaging element block configured from P×Q imagingelements. Further, the solid-state image sensor can be formed such thateach imaging element block includes a control portion, the controlportion is configured at least from a floating diffusion layer, and anamplification transistor and the shared first electrode is connected tothe control portion through the connection portion. The P×Q imagingelements may be configured from a plurality of first type imagingelements hereinafter described or may be configured from at least onefirst type imaging element and one, two or more second type imagingelements hereinafter described.

The solid-state image sensor according to the present disclosure mayadopt, in a case where the imaging element block is configured from fourimaging elements and the first electrodes of the four imaging elementsare shared, a reading out method by which charge accumulated in the fourimaging elements is read out individually by totaling four times or mayadopt another reading out method by which charge accumulated in the fourimaging elements is read out simultaneously by totaling one time. Theformer method is sometimes referred to as “first mode reading outmethod” for the convenience of description and the latter method issometimes referred to as “second mode reading out method” for theconvenience of description. By the first mode reading out method,refinement of an image to be obtained by the solid-state image sensorcan be achieved. By the second mode reading out method, signals obtainedby the four imaging elements are added in order to achieve increase ofthe sensitivity. Switching between the first mode reading out method andthe second mode reading out method can be achieved by providing suitableswitching means in the solid-state image sensor. In the first modereading out method, it is possible for P×Q (for example, 2×2) imagingelements to share one floating diffusion layer by suitably controllingthe timing of a charge transfer period, and P×Q (for example, 2×2)imaging elements configuring the imaging element block are connected toone driving circuit. However, control of the charge accumulatingelectrode is performed for each imaging element.

The solid-state image sensor of the present disclosure can be formedsuch that the first isolation electrode and the second isolationelectrode are provided in a region opposed to a region of thephotoelectric conversion portion with an insulating layer interposedtherebetween. It is to be noted that these isolation electrodes aresometimes referred to as “lower first isolation electrode” and “lowersecond isolation electrode,” respectively, for the convenience ofdescription, and they are sometimes referred to collectively as “lowerisolation electrode.” Alternatively, the solid-state image sensor can beformed such that the first isolation electrode and the second isolationelectrode are provided in a spaced relation from the second electrode onthe photoelectric conversion portion. It is to be noted that theseisolation electrodes are sometimes referred to as “upper first isolationelectrode” and “upper second isolation electrode,” respectively, for theconvenience of description, and they are sometimes referred tocollectively as “upper isolation electrode.” In a case where thesolid-stage image sensor of the 3Bth configuration is configured suchthat the second isolation electrode is provided, it is necessary toconfigure the first isolation electrode and the upper second isolationelectrode from the upper first isolation electrode and the upper secondisolation electrode.

In the solid-state image sensor of the present disclosure, the lowerfirst isolation electrode is arranged in a spaced relation from thefirst electrode and the charge accumulating electrode and surrounds thecharge accumulating electrode. Meanwhile, an orthogonal projection imageof the upper first isolation electrode is positioned in a spacedrelation from orthogonal projection images of the first electrode andthe charge accumulating electrode and surrounds an orthogonal projectionimage of the charge accumulating electrode. In some cases, part of theorthogonal projection image of the upper second isolation electrode andpart of the orthogonal projection image of the charge accumulatingelectrode may overlap with each other.

Reference characters representing potentials applied to the variouselectrodes in the following description are indicated in a table 1below.

TABLE 1 Charge Charge accumulation transfer period period Firstelectrode V₁₁ V₁₂ Second electrode V₂₁ V₂₂ Charge accumulation V₃₁ V₃₂electrode First isolation electrode V_(ES) V_(ES) Second isolationV_(ES) V_(ES) electrode Transfer controlling V₄₁ V₄₂ electrode Chargedischarging V₅₁ V₅₂ electrode

The solid-state image sensor of the present disclosure including thepreferred forms and configurations described above can be formed suchthat it further includes a semiconductor substrate and the photoelectricconversion portion is arranged above the semiconductor substrate. It isto be noted that the first electrode, charge accumulating electrode,second electrode, various isolation electrodes, and various electrodesare connected to a driving circuit hereinafter described.

Further, the solid-state image sensor of the present disclosureincluding the preferred forms and configurations described above can beformed such that the size of the charge accumulating electrode isgreater than that of the first electrode. Where the area of the chargeaccumulating electrode is S₁′ and the area of the first electrode is S₁,though not restrictive, preferably 4≤S₁′/S₁ is satisfied.

The second electrode positioned on the light incidence side may be madecommon to a plurality of imaging elements except for a case in which anupper isolation electrode is formed. In other words, the secondelectrodes can be formed as what is generally called a solid electrode.The photoelectric conversion layer configuring the photoelectricconversion portion can be made common to a plurality of imagingelements. In other words, the solid-state image sensor of the presentdisclosure can be formed such that one photoelectric conversion layer isformed in a plurality of imaging elements.

Further, the solid-state image sensor of the present disclosureincluding the various preferred forms and configurations described abovecan be formed such that the first electrode extends in an openingprovided in an insulating layer and is connected to the photoelectricconversion portion. Alternatively, the solid-state image sensor of thepresent disclosure can be formed such that the photoelectric conversionportion extends in an opening provided in an insulating layer and isconnected to the first electrode, and, in this case, the solid-stateimage sensor of the present disclosure can be formed such that an edgeportion of a top face of the first electrode is covered with theinsulating layer, the first electrode is exposed from a bottom face ofthe opening, and where a face of the insulating layer contacting withthe top face of the first electrode is a first face and another face ofthe insulating layer contacting with a portion of the photoelectricconversion portion opposed to the charge accumulating electrode is asecond face, a side face of the opening has an inclination that expandsfrom the first face toward the second face. Further, the solid-stateimage sensor of the present disclosure can be formed such that the sideface of the opening having the inclination expanding from the first facetoward the second face is positioned on the charge accumulatingelectrode side. It is to be noted that this form includes a form inwhich another layer is formed between the photoelectric conversionportion and the first electrode (for example, a form in which a materiallayer suitable for charge accumulation is formed between thephotoelectric conversion portion and the first electrode).

Further, the solid-state image sensor of the present disclosureincluding the preferred forms and configurations described above can beconfigured such that it further includes a control portion provided on asemiconductor substrate and including a driving circuit, and such thatthe first electrode and the charge accumulating electrode are connectedto the driving circuit, during a charge accumulation period, from thedriving circuit, a potential V₁₁ is applied to the first electrode, apotential V₃₁ is applied to the charge accumulating electrode, andcharge is accumulated into the photoelectric conversion portion, duringa charge transfer period, from the driving circuit, a potential V₁₂ isapplied to the first electrode, a potential V₃₂ is applied to the chargeaccumulating electrode, and charge accumulated in the photoelectricconversion portion is read out into the control portion via the firstelectrode. However, in a case where the potential of the first electrodeis higher than the potential of the second electrode, V₃₁≥V₁₁ andV₃₂<V₁₂ are satisfied, but in a case where the potential of the firstelectrode is lower than the potential of the second electrode, V₃₁≤V₁₁and V₃₂>V₁₂ are satisfied.

Further, the solid-state image sensor of the present disclosureincluding the preferred forms and configurations described above can beformed such that it further includes a transfer controlling electrode(charge transfer electrode) arranged, between the first electrode andthe charge accumulating electrode, in a spaced relation from the firstelectrode and the charge accumulating electrode and arranged in anopposed relation to the photoelectric conversion portion with aninsulating layer interposed therebetween. It is to be noted that suchthe solid-state image sensor of the present disclosure of such a form asjust described is referred to sometimes as “solid-state image sensor ofthe present disclosure including a transfer controlling electrode” forthe convenience of description. Further, in the solid-state image sensorof the present disclosure including the transfer controlling electrode,when a potential applied to the transfer controlling electrode during acharge accumulation period is V₄₁, in the case where the potential ofthe first electrode is higher than the potential of the secondelectrode, it is preferable to satisfy V₄₁≤V₁₁ and V₃₁<V₄₁. Further,when a potential applied to the transfer controlling electrode during acharge transfer period is V₄₂, in the case where the potential of thefirst electrode is higher than the potential of the second electrode, itis preferable to satisfy V₃₂≤V₄₂≤V₁₂.

Further, the solid-state image sensor of the present disclosureincluding the preferred forms and configurations described above can beformed such that it further includes a charge discharging electrodeconnected to the photoelectric conversion portion and arranged in aspaced relation from the first electrode and the charge accumulatingelectrode. It is to be noted that the solid-state image sensor of thepresent disclosure of such a form as just described is referred to as“solid-state image sensor of the present disclosure including the chargedischarging electrode” for the convenience of description. Further, thesolid-state image sensor of the present disclosure including the chargedischarging electrode can be formed such that the charge dischargingelectrode is arranged so as to surround the first electrode and thecharge accumulating electrode (that is, in the form of a picture frame).The charge discharging electrode can be shared by (made common to) aplurality of imaging elements. In a case where the charge dischargingelectrode is provided, it is preferable to configure the variousisolation electrodes from an upper isolation electrode. Then, in thiscase, the solid-state image sensor can be formed such that thephotoelectric conversion portion extends in a second opening provided inthe insulating layer and is connected to the charge dischargingelectrode, an edge portion of a top face of the charge dischargingelectrode is covered with the insulating layer, the charge dischargingelectrode is exposed from a bottom face of the second opening, and, whena face of the insulating layer contacting with the top face of thecharge discharging electrode is a third face and another face of theinsulating layer contacting with a portion of the photoelectricconversion portion opposed to the charge accumulating electrode is asecond face, a side face of the second opening has an inclination thatexpands from the third face toward the second face.

Further, the solid-state image sensor of the present disclosure thatincludes the charge discharging electrode can be configured such that itfurther includes a control portion provided on the semiconductorsubstrate and having a driving circuit, the first electrode, chargeaccumulating electrode, and charge discharging electrode are connectedto the driving circuit, during a charge accumulation period, from thedriving circuit, a potential V₁₁ is applied to the first electrode, apotential V₃₁ is applied to the charge accumulating electrode, and apotential V₅₁ is applied to the charge discharging electrode, and chargeis accumulated into the photoelectric conversion portion, and during acharge transfer period, from the driving circuit, a potential V₁₂ isapplied to the first electrode, a potential V₃₂ is applied to the chargeaccumulating electrode, and a potential V₅₂ is applied to the chargedischarging electrode, and the charge accumulated in the photoelectricconversion portion is read out to the control portion through the firstelectrode. However, in the case where the potential of the firstelectrode is higher than the potential of the second electrode, V₅₁>V₁₁and V₅₂<V₁₂ are satisfied, but, in the case where the potential of thefirst electrode is lower than the potential of the second electrode,V₅₁<V₁₁ and V₅₂>V₁₂ are satisfied.

Further, the solid-state image sensor of the present disclosureincluding the preferred forms and configurations described above can beconfigured such that the charge accumulating electrode is configuredfrom a plurality of charge accumulating electrode segments. It is to benoted that the solid-state image sensor of the present disclosure ofsuch a form as just described is sometimes referred to as “solid-stateimage sensor of the present disclosure including the plurality of chargeaccumulating electrode segments” for the convenience of description. Itis sufficient if the number of charge accumulating electrode segments istwo or more. Further, the solid-state image sensor of the presentdisclosure including the plurality of charge accumulating electrodesegments can be formed such that, in a case where potentials differentfrom each other are applied to N charge accumulating electrode segments,in the case where the potential of the first electrode is higher thanthe potential of the second electrode, the potential applied to thecharge accumulating electrode segment positioned nearest to the firstelectrode (first photoelectric conversion portion segment) during acharge transfer period is higher than the potential applied to thecharge accumulating electrode segment positioned remotest from the firstelectrode (the Nth photoelectric conversion portion segment), and, inthe case where the potential of the first electrode is lower than thepotential of the second electrode, the potential applied to the chargeaccumulating electrode segment positioned nearest to the first electrode(first photoelectric conversion portion segment) during a chargetransfer period is lower than the potential applied to the chargeaccumulating electrode segment position remotest from the firstelectrode (Nth photoelectric conversion portion segment).

Further, the solid-state image sensor of the present disclosureincluding the preferred forms and configurations described above can beformed such that at least a floating diffusion layer and anamplification transistor that configure a control portion are providedon a semiconductor substrate, and the first electrode is connected tothe floating diffusion layer and a gate portion of the amplificationtransistor. Further, in this case, the solid-state image sensor of thepresent disclosure including the preferred forms and configurationsdescribed above is formed such that a reset transistor and a selectiontransistor that configure the control portion are further provided onthe semiconductor substrate, the floating diffusion layer is connectedto one of source/drain regions of the reset transistor, and one ofsource/drain regions of the amplification transistor is connected to oneof source/drain regions of the selection transistor and the other one ofthe source/drain regions of the selection transistor is connected to asignal line.

Alternatively, as a modification of the solid-state image sensor of thepresent disclosure including the preferred forms and configurationsdescribed above, imaging elements of a first configuration to a sixthconfiguration described below can be listed. In other words, in theimaging elements of the first configuration to the sixth configurationin the solid-state image sensor of the present disclosure including thepreferred forms and configurations described above the photoelectricconversion portion is configured from N (where N≥2) photoelectricconversion portion segments, the photoelectric conversion layerconfiguring the photoelectric conversion portion is configured from Nphotoelectric conversion layer segments, the insulating layer isconfigured from N insulating layer segments, in the imaging elements ofthe first configuration to the third configuration, the chargeaccumulating electrode is configured from N charge accumulatingelectrode segments, in the imaging elements of the fourth configurationand the fifth configuration, the charge accumulating electrode isconfigured from N charge accumulating electrode segments arranged in aspaced relation from each other, the nth (where n=1, 2, 3 . . . , N)photoelectric conversion layer segment is configured from the nth chargeaccumulating electrode segment, nth insulating layer segment, and nthphotoelectric conversion layer segment, and a photoelectric conversionportion segment having a higher value of n is positioned farther awayfrom the first electrode.

Then, in the imaging element of the first configuration, the thicknessof the insulating layer segment gradually changes over a range from thefirst photoelectric conversion portion segment to the Nth photoelectricconversion portion segment. Meanwhile, in the imaging element of thesecond configuration, the thickness of the photoelectric conversionlayer segment gradually changes over a range from the firstphotoelectric conversion portion segment to the Nth photoelectricconversion portion segment. Further, in the imaging element of the thirdconfiguration, the material configuring the insulating layer segment isdifferent between photoelectric conversion portion segments adjacent toeach other. Further, in the imaging element of the fourth configuration,the material configuring the charge accumulating electrode segment isdifferent between photoelectric conversion portion segments adjacent toeach other. Further, in the imaging element of the fifth configuration,the area of the charge accumulating electrode segment decreasesgradually over a range from the first photoelectric conversion portionsegment to the Nth photoelectric conversion portion segment. It is to benoted that the area may decrease continuously or may decrease stepwise.

Alternatively, in the imaging element of the sixth configuration in thesolid-state image sensor of the present disclosure including thepreferred forms and configurations described above, when the stackingdirection of the charge accumulating electrode, insulating layer, andphotoelectric conversion portion is a Z direction and the direction awayfrom the first electrode is an X direction, the cross sectional area ofthe stacked portion when the stacked portion at which the chargeaccumulating electrode, insulating layer and photoelectric conversionportion are stacked is cut in a YZ virtual plane changes depending uponthe distance from the first electrode. It is to be noted that the changeof the cross sectional area may be a continuous change or may be astepwise change.

In the imaging elements of the first configuration and the secondconfiguration, the N photoelectric conversion layer segments areprovided continuously, the N insulating layer segments are also providedcontinuously, and the N charge accumulating electrode segments are alsoprovided continuously. In the imaging elements of the thirdconfiguration to the fifth configuration, the N photoelectric conversionlayer segments are provided continuously. Further, in the imagingelements of the fourth configuration and the fifth configuration, whilethe N insulating layer segments are provided continuously, in theimaging element of the third configuration, the N insulating layersegments are provided individually corresponding to the photoelectricconversion portion segments. Further, in the imaging elements of thefourth configuration and the fifth configuration, and in some cases, inthe imaging element of the third configuration, the N chargeaccumulating electrode segments are provided individually correspondingto the photoelectric conversion portion segments. In the imagingelements of the first configuration to the sixth configurations, a samepotential is applied to all of the charge accumulating electrodesegments. Alternatively, in the imaging elements of the fourthconfiguration and the fifth configuration, and in some cases, in theimaging element of the third configuration, potentials different fromeach other may be applied to the N charge accumulating electrodesegments.

In the imaging elements of the first configuration to the sixthconfiguration and the solid-state image sensors of the presentdisclosure to which such imaging elements are applied, the thickness ofthe insulating layer segment is defined, the thickness of thephotoelectric conversion layer segment is defined, the materialconfiguring the insulating layer segment is different, the materialconfiguring the charge accumulating electrode segment is different, thearea of the charge accumulating electrode segment is defined, or thecross sectional area of the stacked portion is defined. Therefore, akind of charge transfer gradient is formed such that charge generated byphotoelectric conversion can be transferred to the first electrode moreeasily and with certainty. Then, as a result, occurrence of anafter-image and occurrence of remaining of charge transfer can beprevented.

As a modification of the solid-state image sensor of the presentdisclosure, a solid-state image sensor can include a plurality of theimaging elements of the first configuration to the sixth configurationdescribed above.

Although, in the imaging elements of the first configuration to thefifth configuration, a photoelectric conversion portion segment having ahigher value of n is positioned farther away from the first electrode,it is decided with reference to the X direction whether or not thephotoelectric conversion portion segment is positioned away from thefirst electrode. Further, although, in the imaging element of the sixthconfiguration, the direction away from the first electrode is determinedas the X direction, the “X direction” is defined in the followingmanner. In other words, a pixel region in which a plurality of imagingelements or stacked type imaging elements is arrayed is configured froma plurality of pixels that is arrayed in a two-dimensional array, thatis, arrayed regularly in the X direction and the Y direction. In a casewhere the planar shape of a pixel is a rectangle, the direction in whicha side of the rectangle nearest to the first electrode extends isdefined as Y direction and a direction orthogonal to the Y direction isdefined as X direction. Alternatively, in a case where the planar shapeof a pixel is a given shape, a general direction in which a line segmentor a curved line nearest to the first electrode is included is definedas Y direction and a direction orthogonal to the Y direction is definedas X direction.

In the following, the imaging elements of the first configuration to thesixth configuration are described in regard to the case in which thepotential of the first electrode is higher than the potential of thesecond electrode. However, in the case where the potential of the firstelectrode is lower than the potential of the second electrode, it issufficient if the potentials are reversed between high and low levels.

In the imaging element of the first configuration, the thickness of theinsulating layer segment gradually changes over a range from the firstphotoelectric conversion portion segment to the Nth photoelectricconversion portion segment. However, the thickness of the insulatinglayer segment may gradually increase or gradually decrease, and by this,a kind of charge transfer gradient is formed.

In a case where the charge to be accumulated is electrons, it issufficient to adopt a configuration that the thickness of the insulatinglayer segment gradually increases, but in a case where the charge to beaccumulated is positive holes, it is sufficient to adopt a configurationthat the thickness of the insulating layer segment gradually decreases.In those cases, if such a state as |V₃₁|≥|V₁₁| is entered during acharge accumulation period, then the nth photoelectric conversionportion segment can accumulate a greater amount of charge than the(n+1)th photoelectric conversion portion segment, and a strongerelectric field is applied in the nth photoelectric conversion portionsegment than that in the (n+1)th photoelectric conversion portionsegment. Therefore, a flow of charge from the first photoelectricconversion portion segment to the first electrode can be prevented withcertainty. Then, if such a state as |V₃₂|<|≤V₁₂| is entered during acharge transfer period, then a flow of charge from the firstphotoelectric conversion portion segment to the first electrode and aflow of charge from the (n+1)th photoelectric conversion portion segmentto the nth photoelectric conversion portion segment can be assured withcertainty.

In the imaging element of the second configuration, the thickness of thephotoelectric conversion layer segment gradually changes over a rangefrom the first photoelectric conversion portion segment to the Nthphotoelectric conversion portion segment. However, the thickness of thephotoelectric conversion layer segment may gradually increase orgradually decrease. By this, a kind of charge transfer gradient isformed.

In the case where the charge to be accumulated is electrons, it issufficient to adopt a configuration that the thickness of thephotoelectric conversion layer segment gradually increases, and in thecase where the charge to be accumulated is positive holes, it issufficient to adopt a configuration that the thickness of thephotoelectric conversion layer segment gradually decreases. Further, inthe case where the thickness of the photoelectric conversion layersegment gradually increases, if such a state as V₃₁≥V₁₁ is enteredduring a charge accumulation period, but in the case where the thicknessof the photoelectric conversion layer segment gradually degreases, ifsuch a state as V₃₁≤V₁₁ is entered during a charge accumulation period,then to the nth photoelectric conversion portion segment, a strongerelectric field than to the (n+1)th photoelectric conversion portionsegment is applied, and a flow of charge from the first photoelectricconversion portion segment to the first electrode can be prevented withcertainty. Then, during a charge transfer period, in the case where thethickness of the photoelectric conversion layer segment graduallyincreases, if such a state as V₃₂<V₁₂ is entered, but in the case wherethe thickness of the photoelectric conversion layer segment graduallydecreases, if such a state as V₃₂>V₁₂ is entered, then a flow of chargefrom the first photoelectric conversion portion segment to the firstelectrode and a flow of charge from the (n+1)th photoelectric conversionportion segment to the nth photoelectric conversion portion segment canbe assured with certainty.

In the imaging element of the third configuration, the materialconfiguring the insulating layer segment is different between adjacentphotoelectric conversion portion segments, and by this, a kind of chargetransfer gradient is formed. However, preferably the value of therelative permittivity of the material configuring the insulating layersegments gradually decreases over a range from the first photoelectricconversion portion segment to the Nth photoelectric conversion portionsegment. Further, if, by adopting such a configuration as justdescribed, such a state as V₃₁≥V₁₁ is entered during a chargeaccumulation period, then the nth photoelectric conversion portionsegment can accumulate a greater amount of charge than the (n+1)thphotoelectric conversion portion segment. Then, if such a state asV₃₂<V₁₂ is entered during a charge transfer period, then a flow ofcharge from the first photoelectric conversion portion segment to thefirst electrode and a flow of charge from the (n+1)th photoelectricconversion portion segment to the nth photoelectric conversion portionsegment can be assured with certainty.

In the imaging element of the fourth configuration, the materialconfiguring the charge accumulating electrode segment is differentbetween adjacent photoelectric conversion portion segments, and by this,a kind of charge transfer gradient is formed. However, preferably thevalue of the work function of the material configuring the insulatinglayer segment gradually increases in a range from the firstphotoelectric conversion portion segment to the Nth photoelectricconversion portion segment. Further, by adopting such a configuration asjust described, a potential gradient advantageous to signal chargetransfer can be formed without relying upon the positive/negative of thevoltage (potential).

In the imaging element of the fifth configuration, the area of thecharge accumulating electrode segment gradually decreases over a rangefrom the first photoelectric conversion portion segment to the Nthphotoelectric conversion portion segment. Since a kind of chargetransfer gradient is formed by this, if such a state of V₃₁≥V₁₁ isentered during a charge accumulation period, then the nth photoelectricconversion portion segment can accumulate a greater amount of chargethan the (n+1)th photoelectric conversion portion segment. Then, if sucha state as V₃₂<V₁₂ is entered during a charge transfer period, then aflow of charge from the first photoelectric conversion portion segmentto the first electrode and a flow of charge from the (n+1)thphotoelectric conversion portion segment to the nth photoelectricconversion portion segment can be assured with certainty.

In the imaging element of the sixth configuration, the sectional area ofthe stacked portion changes depending upon the distance from the firstelectrode, and by this, a kind of charge transfer gradient is formed. Inparticular, if a configuration is adopted in which the thickness of thecross section of the stacked portion is fixed and the width of thesectional area of the stacked portion decreases away from the firstelectrode, then similarly as in the description of the imaging elementof the fifth configuration, if such a state as V₃₁≥V₁₁ is entered duringa charge accumulation period, then a region nearer to the firstelectrode can accumulate a greater amount of charge than a regionremoter to the first electrode. Accordingly, if such a state as V₃₂<V₁₂is entered during a charge transfer period, then a flow of charge fromthe region nearer to the first electrode to the first electrode and aflow of charge from the remoter region to the nearer region can beassured with certainty. On the other hand, if a configuration is adoptedin which the width of the cross section of the stacked portion is fixedand the thickness of the cross section of the stacked portion, moreparticularly, the thickness of the insulating layer segment, graduallyincreases, then similarly as in the description of the imaging elementof the first configuration, if such a state as V₃₁≥V₁₁ is entered duringa charge accumulation period, then the region nearer to the firstelectrode can accumulate a greater amount of charge than the regionremoter to the first electrode and a stronger electric field is appliedin the nearer region than that in the remoter region, by which a flow ofcharge from the region nearer to the first electrode to the firstelectrode can be prevented with certainty. Then, if such a state asV₃₂<V₁₂ is entered during a charge transfer period, then a flow ofcharge from the region nearer to the first electrode to the firstelectrode and a flow of charge from the remoter region to the nearerregion can be assured with certainty. Further, if a configuration isadopted in which the thickness of the photoelectric conversion layersegment gradually increases, then similarly as in the description of theimaging element of the second configuration, if such a state as V₃₁≥V₁₁is entered during a charge accumulation period, then a stronger electricfield is applied in the region nearer to the first electrode than thatin the region remoter to the first electrode, and a flow of charge fromthe region nearer to the first electrode to the first electrode can beprevented with certainty. Then, if such a state as V₃₂<V₁₂ is enteredduring a charge transfer period, then a flow of charge from the regionnearer to the first electrode to the first electrode and a flow ofcharge from the remoter region to the nearer region can be assured withcertainty.

Further, the solid-state image sensor of the present disclosureincluding the preferred forms and configurations described above can beformed such that light is incident from the second electrode side and ashading layer is formed on the light incidence side rather near to thesecond electrode. Alternatively, the solid-state image sensor of thepresent disclosure can be formed such that light is incident from thesecond electrode side and light is not incident to the first electrode(in some cases, to the first electrode and the transfer controllingelectrode). Further, in this case, the solid-state image sensor of thepresent disclosure can be formed such that a shading layer is formedabove the first electrode (in some cases, above the first electrode andthe transfer controlling electrode) on the light incidence side rathernear to the second electrode or can be formed such that an on-chipmicrolens is provided above the charge accumulating electrode and thesecond electrode such that light incident to the on-chip microlens isfocused on the charge accumulating electrode. Here, the shading layermay be arranged above a light incidence side face of the secondelectrode or on the light incident side face of the second electrode. Insome cases, the shading layer may be formed on the second electrode. Asthe material for configuring the shading layer, chromium (Cr), copper(Cu), aluminum (Al), tungsten (W), and a resin that does not transmitlight (for example, a polyimide resin) can be exemplified.

As the solid-state image sensor of the present disclosure, particularlyan imaging element (referred to as “blue light imaging element of thefirst type” for the convenience of description) that includes aphotoelectric conversion portion (referred to as “blue lightphotoelectric conversion portion of the first type” for the convenienceof description) that absorbs blue light (light of 425 to 495 nm) and hasa sensitivity to blue light, an imaging element (referred to as “greenlight imaging element of the first type” for the convenience ofdescription) that includes a photoelectric conversion portion (referredto as “green light photoelectric conversion portion of the first type”for the convenience of description) that absorbs green light (light of495 to 570 nm) and has a sensitivity to green light, and an imagingelement (referred to as “red light imaging element of the first type”for the convenience of description) that includes a photoelectricconversion portion (referred to as “red light photoelectric conversionportion of the first type” for the convenience of description) thatabsorbs red light (light of 620 to 750 nm) and has a sensitivity to redlight can be listed. In addition, a conventional imaging element thatdoes not include a charge accumulating electrode and has the sensitivityto blue light is referred to as “blue light imaging element of thesecond type” for the convenience of description, such a conventionalimaging element having the sensitivity to green light is referred to as“green light imaging element of the second type” for the convenience ofdescription, and such a conventional imaging element having thesensitivity to red light is referred to as “red light imaging element ofthe second type” for the convenience of description. Further, aphotoelectric conversion portion configuring a blue light imagingelement of the second type is referred to as “blue light photoelectricconversion portion of the second type” for the convenience ofdescription, a photoelectric conversion portion configuring a greenlight imaging element of the second type is referred to as “green lightphotoelectric conversion portion of the second type” for the convenienceof description, and a photoelectric conversion portion configuring a redlight imaging element of the second type is referred to as “red lightphotoelectric conversion portion of the second type” for the convenienceof description.

Although the stacked type imaging element in the present disclosureincludes at least one solid-state image sensor (photoelectric conversiondevice) of the present disclosure, particularly, for example,

[A] a stacked type imaging element configured and structured such thatthe blue light photoelectric conversion portion of the first type, greenlight photoelectric conversion portion of the first type, and red lightphotoelectric conversion portion of the first type are stacked in thevertical direction, and

control portions of the blue light imaging element of the first type,green light imaging element of the first type, and red light imagingelement of the first type are provided on a semiconductor substrate,

[B] a stacked type imaging element configured and structured such thatthe blue light photoelectric conversion portion of the first type andthe green light photoelectric conversion portion of the first type arestacked in the vertical direction, and

the red light photoelectric conversion portion of the second type isarranged below the two layers of the photoelectric conversion portionsof the first type, and

control portions of the blue light imaging element of the first type,green light imaging element of the first type, and red light imagingelement of the second type are provided on a semiconductor substrate,

[C] a stacked type imaging element configured and structured such thatthe blue light photoelectric conversion portion of the second type andthe red light photoelectric conversion portion of the second type arearranged below the green light photoelectric conversion portion of thefirst type, and

control portions of the green light imaging element of the first type,blue light imaging element of the second type, and red light imagingelement of the second type are provided on a semiconductor substrate,and

[D] a stacked type imaging element configured and structured such thatthe green light photoelectric conversion portion of the second type andthe red light photoelectric conversion portion of the second type arearranged below the blue light photoelectric conversion portion of thefirst type, and

control portions of the blue light imaging element of the first type,green light imaging element of the second type, and red light imagingelement of the second type are provided on a semiconductor substrate.

It is to be noted that the order of arrangement of the photoelectricconversion portions of the imaging elements in the vertical directionpreferably is the order of the blue light photoelectric conversionportion, green light photoelectric conversion portion, and red lightphotoelectric conversion portion from the light incidence direction, orthe order of the green light photoelectric conversion portion, bluelight photoelectric conversion portion, and red light photoelectricconversion portion from the light incidence direction. This is becauselight of a shorter wavelength is absorbed in a higher efficiency on theincidence surface side. Since red light has the longest wavelength amongthe three colors, preferably the red light photoelectric conversionportion is positioned in the lowermost layer as viewed from the lightincidence face. One pixel is configured from a stacked structure of theimaging elements. Here, preferably the red light photoelectricconversion portion of the first type is configured, for example, from anorganic material and is arranged in the lowermost layer of the stackedstructure of the imaging elements of the first type but higher than theimaging elements of the second type. Alternatively, an infrared lightphotoelectric conversion portion of the second type may be providedbelow the photoelectric conversion portions of the first type.

In the imaging elements of the first type, for example, the firstelectrode is formed on an interlayer insulating layer provided on thesemiconductor substrate. The imaging element formed on the semiconductorsubstrate may be formed as that of the back-illuminated type or as thatof the front-illuminated type.

In a case where the photoelectric conversion portion is configured fromphotoelectric conversion layer formed from an organic material, thephotoelectric conversion layer can be formed in any of four formsincluding

(1) a form in which the photoelectric conversion layer is configuredfrom a p-type organic semiconductor,

(2) a form in which the photoelectric conversion layer is configuredfrom an n-type organic semiconductor,

(3) a form in which the photoelectric conversion layer is configuredfrom a stacked structure of a p-type organic semiconductor layer/n-typeorganic semiconductor layer, a stacked structure of a p-type organicsemiconductor layer/mixture layer (bulk hetero structure) of a p-typeorganic semiconductor and an n-type organic semiconductor/n-type organicsemiconductor layer, a stacked structure of a p-type organicsemiconductor layer/mixture layer (bulk hetero structure) of a p-typeorganic semiconductor and an n-type organic semiconductor, or a stackedstructure of an n-type organic semiconductor layer/mixture layer (bulkhetero structure) of a p-type organic semiconductor and an n-typeorganic semiconductor, and

(4) a form in which the photoelectric conversion layer is configuredfrom a mixture (bulk hetero structure) of a p-type organic semiconductorand an n-type organic semiconductor.

It is to be noted that a configuration in which the layering order ischanged as desired can be applied.

As the p-type organic semiconductor, naphthalene derivatives, anthracenederivatives, phenanthrene derivatives, pyrene derivatives, perylenederivatives, tetracene derivatives, pentacene derivatives, quinacridonederivatives, thiophene derivatives, thienothiophene derivatives,benzothiophene derivatives, benzothionopyridine benzothiophenederivatives, triallylamine derivatives, carbazole derivatives, perylenederivatives, picene derivatives, chrysene derivatives, fluoranthenederivatives, phthalocyanine derivatives, subphthalocyanine derivatives,subporphyrazine derivatives, metal complexes with a heterocycliccompound as a ligand, polythiophene derivatives, polybenzothiadiazolederivatives, polyfluorene derivatives, and so forth are applicable. Asthe n-type organic semiconductors, fullerenes and fullerenes derivatives<for example, fullerenes such as C60, C70, and C74 (higher fullerenes),encapsulating fullerenes and so forth) or fullerenes derivatives (forexample, fullerene fluorides, PCBM fullerene compounds, fullerenemultimers, and so forth)>, organic semiconductors whose HOMO and LUMOare greater (deeper) than those of p-type organic semiconductors, andtransparent inorganic metal oxides are applicable. As the n-type organicsemiconductors, particularly, heterocyclic compounds containing nitrogenatoms, oxygen atoms, or sulfur atoms such as organic molecules thathave, at a molecular skeleton thereof, pyridine derivatives, pyrazinederivatives, pyrimidine derivatives, triazine derivatives, quinolinederivatives, quinoxaline derivatives, isoquinoline derivatives, acridinederivatives, phenazine derivatives, phenanthroline derivatives,tetrazole derivatives, pyrazole derivatives, imidazole derivatives,thiazole derivatives, oxazole derivatives, imidazole derivatives,benzimidazole derivatives, benzotriazole derivatives, benzoxazolederivatives, benzoxazole derivatives, carbazole derivatives, benzofuranderivatives, dibenzofuran derivatives, subporphyrazine derivatives,polyphenylene vinylene derivatives, polybenzothiadiazole derivatives,polyfluorene derivatives, or the like, organometallic complexes, andsubphthalocyanine derivatives are applicable.

As a group or the like included in the fullerene derivatives, halogenatoms; linear, branched, or cyclic alkyl groups or phenyl groups; groupshaving a linear or condensed-ring aromatic compound; groups having ahalide; partial fluoroalkyl groups; perfluoroalkyl groups; cyril alkylgroups; cyril alkoxy groups; arylsilyl groups; aryl sulfanyl groups;alkyl sulfanyl groups; aryl sulfonyl groups; alkyl sulfonyl groups; arylsulfide groups; alkyl sulfide groups; amino groups; alkyl amino groups;aryl amino groups; hydroxy groups; alcoxy groups; acyl amino groups;acyloxy groups; carbonyl groups; carboxy groups; carboxamide groups;carboalcoxy groups; acyl groups; sulfonil groups; cyano groups; nitrogroups; groups having a chalcogenide; phosphine groups; phosphon groups;and derivatives of them are applicable. Though not restrictive, thethickness of the photoelectric conversion layer configured from anorganic material (sometimes referred to as “organic photoelectricconversion layer”) is, for example, 1×10⁻⁸ to 5×10⁻⁷ m, preferably,2.5×10⁻⁸ to 3×10⁻⁷ m, more preferably, 2.5×10⁻⁸ to 2×10⁻⁷ m, mostpreferably, 1×10⁻⁷ to 1.8×10⁻⁷ m can be exemplified. It is to be notedthat, although organic semiconductors are frequently classified into thep type and the n type, the p type signifies that positive holes aretransported readily and the n type signifies that electrons aretransported readily, and the interpretation that the organicsemiconductor has positive holes or electrons as multiple carriers ofthermal excitation like inorganic semiconductors is not restrictive.

Meanwhile, as a material for configuring an organic photoelectricconversion layer for photoelectrically conversing green light, forexample, a rhodamine pigment, a melacianin pigment, a quinacridonederivative, a subphthalocyanine pigment (subphthalocyanine derivative),and so forth are applicable. As a material for configuring an organicphotoelectric conversion layer for photoelectrically converting bluelight, for example, a coumarin acid pigment, tris 8 hydrixi quinolialuminum (Alq3), a melacianin pigment, and so forth are applicable.Further, as a material for configuring an organic photoelectricconversion layer for photoelectrically converting red light, forexample, a phthalocyanine pigment and a subphthalocyanine pigment(subphthalocyanine derivative) are applicable.

Alternatively, as an inorganic material for configuring a photoelectricconversion layer, crystalline silicon, amorphous silicon,microcrystalline silicon, crystalline selenium, amorphous selenium, andCIGS (CuInGaSe), CIS (CuInSe₂), CuInS₂, CuAlS₂, CuAlSe₂, CuGaS₂,CuGaSe₂, AgAlS₂, AgAlSe₂, AgInS₂, and AgInSe₂, which are calcopalitecompounds, GaAs, InP, AlGaAs, InGaP, AlGaInP, and InGaAsP, which areIII-V group compounds, or such compound semiconductors as CdSe, CdS,In₂Se₃, In₂S₃, Bi₂Se₃, Bi₂S₃, ZnSe, ZnS, PbSe, PbS, and so forth areapplicable. In addition, also it is possible to use quantum dots formedfrom those materials for the photoelectric conversion layer.

Alternatively, the photoelectric conversion portion can be formed in astacked structure of a lower layer semiconductor layer and an upperlayer photoelectric conversion layer. By providing the lower layersemiconductor layer in this manner, for example, it is possible toprevent recombination upon charge accumulation. Further, the chargetransfer efficiency of charge accumulated in the photoelectricconversion portion to the first electrode can be increased. Further, itis possible to temporarily hold charge generated in the photoelectricconversion portion and control the transfer timing and so forth.Further, generation of dark current can be suppressed. It is sufficientif the material for configuring the upper layer photoelectric conversionlayer is selected suitably from the various materials that configure thephotoelectric conversion layer described hereinabove. On the other hand,as the material for configuring the lower layer semiconductor layer, itis preferable to use a material that has a high value of the band gapenergy (for example, a value of the band gap energy of 3.0 eV or more)and besides has a mobility higher than that of the material forconfiguring the photoelectric conversion layer. In particular, oxidesemiconductor materials; transition metal dichalcogenide; siliconcarbide; diamond; graphene; carbon nanotube; and organic semiconductormaterials such as condensed polycyclic hydride compounds and condensedhydrocyclic compounds, and more particularly, as the oxide semiconductormaterial, indium oxide, gallium oxide, zinc oxide, tin oxide, materialscontaining at least one of these oxides, materials with a dopant addedto these materials, more particularly, for example, IGZO, ITZO, IWZO,IWO, ZTO, ITO-SiO_(x) materials, GZO, IGO, ZnSnO₃, AlZnO, GaZnO, andInZnO are applicable. Further, materials containing CuI, InSbO₄, ZnMgO,CuInO₂, MgIn₂O₄, CdO, or the like are applicable. However, thesematerials are not restrictive. Alternatively, as a material forconfiguring the lower layer semiconductor layer, in the case wherecharge to be accumulated is electrons, a material having ionizationpotential higher than the ionization potential of the material thatconfigures the upper layer photoelectric conversion layer is applicable,and in the case where charge to be accumulated is positive holes, amaterial having electron affinity lower than the electron affinity ofthe material that configures the upper layer photoelectric conversionlayer is applicable. Alternatively, the impurity concentration of thematerial that configures the lower layer semiconductor layer preferablyis 1×10¹⁸ cm⁻³ or less. The lower layer semiconductor layer may have asingle layer configuration or may have a multilayer configuration.Further, the material that configures the lower layer semiconductorlayer positioned above the charge accumulating electrode and thematerial that configures the lower layer semiconductor layer positionedabove the first electrode may be made different from each other.

A single plate type color solid-state image sensor can be configuredfrom the solid-state image sensors of the present disclosure.

In the solid-state image sensor of the present disclosure including astacked type imaging element, different from a solid-state image sensorthat includes imaging elements of a Bayer array (that is, spectroscopyof blue, green, and red is not performed using a color filter), onepixel is configured by stacking imaging elements having sensitivities tolight of a plurality of different wavelengths in an incidence directionof light in the same pixel, and therefore, improvement of thesensitivity and improvement of the pixel density per unit volume can beachieved. Further, since organic materials have a high absorptioncoefficient, the film thickness of the organic photoelectric conversionlayer can be reduced in comparison with a conventional Si typephotoelectric conversion layer, and leak of light from an adjacent pixelor limitation to the incidence angle of light is moderated. Furthermore,although a conventional Si type imaging element suffers from false colorbecause it generates a color signal by performing an interpolationprocess among pixels of three colors, in the solid-state image sensor ofthe present disclosure that includes the stacked type imaging element,appearance of false color can be suppressed. Further, since the organicphotoelectric conversion layer itself functions also as a color filter,even if a color filter is not arranged, color separation can beperformed.

On the other hand, in the solid-state image sensor of the presentdisclosure that includes not the stacked type imaging element but theimaging element, by using a color filter, a requirement for aspectroscopic characteristic of blue, green and, red can be moderated,and high mass productivity is achieved. As the array of imaging elementsin the solid-state image sensor of the present disclosure, in additionto a Bayer array, an interline array, a G stripe RB checkered array, a Gstripe RB complete checkered array, a checkered complementary colorarray, a stripe array, an oblique stripe array, a primary colordifference array, a field color difference sequential array, a framecolor difference sequential array, a MOS type array, an improved MOStype array, a frame interleave array, and a field interleave array areapplicable. Here, one pixel (or subpixel) can be configured from asingle imaging element.

The solid-state image sensor of the present disclosure is configuredfrom a plurality of pixels arrayed regularly in a two-dimensional array.A pixel region is usually configured from an effective pixel region inwhich light is actually received and signal charge generated byphotoelectric conversion is amplified and read out to a driving circuit,and a black reference pixel region for outputting optical black thatbecomes a reference for the black level. The black reference pixelregion is usually arranged on an outer peripheral portion of theeffective pixel region.

In the solid-state image sensor of the present disclosure including thepreferred forms and configurations described above, light is irradiatedand photoelectric conversion occurs in the photoelectric conversionportion, whereupon carrier separation into positive holes (holes) andelectrons is performed. Then, the electrode from which the positiveholes are extracted is determined as an anode and the electrode fromwhich the electrons are extracted is determined as a cathode. Not only aform in which the first electrode configures the anode and the secondelectrode configures the cathode but also a form in which conversely thefirst electrode configures the cathode and the second electrodeconfigures the anode are available.

In the case where a stacked type imaging element is configured, it canbe configured such that the first electrode, the charge accumulatingelectrode, various isolation electrodes, the transfer controllingelectrode, the charge discharging electrode, and the second electrodeare formed from a transparent conductive material. It is to be notedthat the first electrode, the charge accumulating electrode, variousisolation electrodes, the transfer controlling electrode, and the chargedischarging electrode are sometimes referred to collectively as “firstelectrode and so forth.” Alternatively, in the a where the solid-stateimage sensor of the present disclosure is arranged on a plane, forexample, like a Bayer array, the stacked type imaging element can beconfigured such that the second electrode is formed from a transparentconductive material and the first electrode, the charge accumulatingelectrode, and so forth are formed from a metal material. In this case,the stacked type imaging element can be configured particularly suchthat the second electrode positioned on the light incidence side isformed from a transparent conductive material and the first electrodeand so forth are formed, for example, from Al—Nd (alloy of aluminum andneodymium) or ASC (alloy of aluminum, samarium, and copper). It is to benoted that an electrode made of a transparent conductive material issometimes referred to as “transparent electrode.” Here, the band gapenergy of the transparent conductive material is 2.5 eV or more,preferably 3.1 eV or more. As the transparent conductive materialconfiguring the transparent electrode, a metal oxide having conductivityis applicable. In particular, indium oxide, indium tin oxide (ITO,Indium Tin Oxide, including In₂O₃ doped with Sn, crystalline ITO, andamorphous ITO), indium zinc oxide (IZO, Indium Zinc Oxide) where indiumis added as a dopant to zinc oxide, indium gallium oxide (IGO) whereindium is added as a dopant to gallium oxide, indium gallium zinc oxide(IGZO, In—GaZnO₄) where indium and gallium are added as a dopant to zincoxide, indium tin zinc oxide (ITZO) where indium and tin are added as adopant to zinc oxide, IFO (F-doped In₂O₃), tin oxide (SnO₂), ATO(Sb-doped SnO₂), FTO (F-doped SnO₂), zinc oxide (including ZnO dopedwith a different element), aluminum zinc oxide (AZO) where aluminum isadded as a dopant to zinc oxide, gallium zinc oxide (GZO) where galliumis added as a dopant to zinc oxide, titanium oxide (TiO₂), niobiumtitanium oxide (TNO) where niobium is added as a dopant to titaniumoxide, antimony oxide, spinel type oxide, and an oxide having a YbFe₂O₄structure are applicable. Alternatively, a transparent electrodeincluding gallium oxide, titanium oxide, niobium oxide, nickel oxide,and so forth as a base layer is applicable. As the thickness of thetransparent electrode, 2×10⁻⁸ to 2×10⁻⁷ m, preferably 3×10⁻⁸ to 1×10⁻⁷m, are applicable. In a case where transparency is required for thefirst electrode, it is also preferable that the other electrodes areconfigured from a transparent conductive material from the point of viewof simplification of the manufacturing process.

Alternatively, in a case where the transparency is not required, aconductive material for configuring an anode having a function as anelectrode for extracting positive holes is preferably configured from aconductive material having a high work function (for example, φ=4.5 to5.5 eV). In particular, gold (Au), silver (Ag), chromium (Cr), nickel(Ni), palladium (Pd), platinum (Pt), iron (Fe), iridium (Ir), germanium(Ge), osmium (Os), rhenium (Re), and tellurium (Te) can be exemplified.On the other hand, a conductive material for configuring a cathodehaving a function as an electrode for extracting electrons is preferablyconfigured from a conductive material having a low work function (forexample, φ=3.5 to 4.5 eV). In particular, alkali metals (for example,Li, Na, K, and so forth) and fluorides or oxides of the same, alkalineearth metals (for example, Mg, Ca, and so forth) and fluorides or oxidesof the same, aluminum (Al), zinc (Zn), tin (Sn), thallium (Tl),sodium-potassium alloys, aluminum-lithium alloys, magnesium-silveralloys, rare earth metals such as indium and ytterbium, or alloys ofthem are applicable. Alternatively, as a material for configuring ananode or a cathode, conductive materials such as metals such as platinum(Pt), gold (Au), palladium (Pd), chromium (Cr), nickel (Ni), aluminum(Al), silver (Ag), tantalum (Ta), tungsten (W), copper (Cu), titanium(T), indium (In), tin (Sn), iron (Fe), cobalt (Co), and molybdenum (Mo),alloys containing such metal elements, conductive particles configuredfrom those metals, conductive particles of alloys containing thosemetals, polycrystalline silicon containing impurities, carbon-basedmaterials, oxide semiconductors, carbon nanotubes, graphene, and soforth are applicable. Further, as a material for configuring an anode ora cathode, such an organic material (conductive polymers) aspoly(3,4-ethylenedioxythiophene)/polystyrene sulfonic acid [PEDOT/PSS]is applicable. Further, such conductive materials may be used as anelectrode by mixing it into binder (polymer) to form paste or ink andhardening the paste or the ink.

As a film formation method of the first electrode or the like and thesecond electrode (anode and cathode), a dry method or a wet method canbe used. As the dry method, a physical vapor deposition method (PVDmethod) and a chemical vapor deposition method (CVD method) areapplicable. As a film formation method in which the PVD method is used,a vapor deposition method that uses resistor heating or high frequencyheating, an EB (electron beam) deposition method, various sputteringmethods (magnetron sputtering method, RF-DC combined bias sputteringmethod, ECR sputtering method, opposed target sputtering method, andhigh frequency sputtering method), an ion plating method, a laserablation method, a molecular beam epitaxy method, and a laser transfermethod are applicable. Meanwhile, as the CVD method, a plasma CVDmethod, a thermal CVD method, an organic metal (MO) CVD method, and anoptical CVD method are applicable. On the other hand, as the wet typemethod, such methods as an electroplating method or an electrolessplating method, a spin coating method, an ink jet method, a spraycoating method, a stamp method, a micro contact print method, a flexoprinting method, an offset printing method, a gravure printing method,and a dip method are applicable. As the patterning method, chemicaletching such as shadow mask, laser transfer, or photolithography,physical etching by ultraviolet rays or a laser and so forth areapplicable. As a flattening technology for the first electrode and soforth or the second electrode, a laser flattening method, a reflowmethod, a CMP (Chemical Mechanical Polishing) method, and so forth canbe used.

As a material for configuring an insulating layer, an interlayerinsulating layer, an insulating film, and an interlayer insulating film,not only an inorganic insulating material exemplified by a silicon oxidematerial; silicon nitride (SiN_(Y)); and a metal oxide high dielectricinsulating material such as aluminum oxide (Al₂O₃), but alsopolymethylmethacrylate (PMMA); polyvinyl phenol (PVP); polyvinyl alcohol(PVA); polyimide; polycarbonate (PC); polyethylene terephthalate (PET);polystyrene; silanol derivative (silane coupling agent) such as N-2(amino ethyl) 3-aminopropyltrimethoxysillane (AEAPTMS),3-mercaptpropyltrimethoxysilane (MPTMS), or octadecyltrichlorosilane(OTS); novolac type phenolic resins; fluorine resins; and organicinsulating materials (organic polymers) exemplified by linearhydrocarbons having a functional group that can be attached to thecontrol electrode at one end thereof such as octadecane thiol or dodecylisocyanate are applicable, and combinations of them can also be used. Itis to be noted that, as the silicon oxide materials, silicon oxide(SiO_(X)), BPSG, PSG, BSG, AsSG, PbSG, silicon oxynitride (SiON), SOG(spin-on-glass), and low dielectric materials (for example, polyallylether, cycloperfluorocarbon polymer and benzocyclobutene, cyclicfluororesin, polytetrafluoroethylene, aryl fluoride ether, polyimidefluoride, amorphous carbon, and organic SOG) can be exemplified.

The configuration and structure of the floating diffusion layer, theamplification transistor, the reset transistor, and the selectiontransistor that configure the control portion can be made similar to theconfiguration and structure of a conventional floating diffusion layer,amplification transistor, reset transistor, and selection transistor.The driving circuit can also have a well-known configuration andstructure.

Although the first electrode is connected to the floating diffusionlayer and the gate portion of the amplification transistor, it issufficient if a contact hole portion for the connection between thefirst electrode and the floating diffusion layer and the gate portion ofthe amplification transistor is formed. As the material for configuringthe contact hole portion, polysilicon doped with an impurity, highmelting point metals and metal silicide such as tungsten, Ti, Pt, Pd,Cu, TiW, TiN, TiNW, WSi₂, or MoSi₂ and stacked structures (for example,Ti/TiN/W) of layers made of such materials can be exemplified.

A first carrier blocking layer may be provided between the organicphotoelectric conversion layer and the first electrode, and a secondcarrier blocking layer may be provided between the organic photoelectricconversion layer and the second electrode. Further, a first chargeinjection layer may be provided between the first carrier blocking layerand the first electrode, and a second charge injection layer may beprovided between the second carrier blocking layer and the secondelectrode. For example, as the material for configuring the chargeinjection layer, alkali metals such as lithium (Li), sodium (Na), orpotassium (K) and their fluorides and oxides and alkaline earth metalssuch as magnesium (Mg) and calcium (Ca) and their fluorides and oxidesare applicable.

As the film formation method of the various organic layers, a dry filmformation method and a wet film formation method are applicable. As thedry film formation method, a vacuum deposition method that uses resistorheating, high frequency heating, or electron beam heating, a flashdeposition method, a plasma deposition method, an EB deposition method,various sputtering methods (2-pole sputtering method, a direct current(DC) sputtering method, a DC magnetron sputtering, a high frequencysputtering method, a magnetron sputtering method, an RF-DC combined biassputtering method, an ECR sputtering method, an opposed targetsputtering method, a high frequency sputtering method, and an ion beamsputtering method), a high frequency sputtering method, and an ion beamsputtering method), a DC method, an RF method, a multicathode method, anactivation reaction method, an electric field deposition method, variousion plating methods such as a high frequency ion plating method and areactive ion plating method, a laser ablation method, a molecular beamepitaxy method, a laser transfer method, and a molecular beam epitaxymethod (MBE method) are applicable. Meanwhile, as the CVD method, aplasma CVD method, a thermal CVD method, an MOCVD method, and an opticalCVD method are applicable. On the other hand, as the wet type method,particularly, a spin coating method; an immersion method; a cast method;a micro contact print method; a drop cast method; various printingmethods such as a screen printing method and an ink jet printing method,an offset printing method, a gravure printing method, or a flexoprinting method; a stamp method; a spray method; and various coatingmethods such as an airdactor coater method, a blade coater method, a rodcoater method, a knife coater method, a squeeze coater method, a reverseroll coater method, a transfer roll coater method, a gravure coatermethod, a kiss coater method, a cast coater method, a spray coatermethod, a slit orifice coater method, and a calendar coater method canbe exemplified. It is to be noted that, in the application method, as asolvent, non-polar or low-polar organic solvents such as toluene,chloroform, hexane, and ethanol can be exemplified. As the patterningmethod, chemical etching such as shadow mask, laser transfer, orphotolithography, physical etching by ultraviolet rays, a laser, or thelike and so froth are applicable. As a flattening method for the variousorganic layers, a laser flattening method, a reflow method, and so forthcan be used.

Two or more of the imaging elements of the first configuration to thesixth configuration including the preferred forms and configurationsdescribed above can be suitably combined as desired.

In the solid-state image sensors, an on-chip microlens or a shadinglayer may be provided as described above as occasion demands, and adriving circuit and wirings for driving the imaging elements areprovided. As occasion demands, a shutter for controlling incidence oflight to the imaging element may be arranged, or an optical cut filtermay be provided according to an object of the solid-state image sensor.

For example, in a case where a solid-state image sensor is stacked witha reading out integrated circuit (ROIC), by placing a driving substrateon which a reading out integrated circuit and a connection region madeof cupper (Cu) are formed and an imaging element on which a connectionregion is formed one on the other such that the connection regionscontact with each other and then joining the connection regions to eachother, they can be stacked, and it is also possible to join theconnection regions to each other using solder bumps or the like.

Further, a driving method for driving the solid-state image sensor ofthe present disclosure can be made a driving method for a solid-stateimage sensor that repeats the steps of discharging, in all imagingelements all at once, while charge is accumulated into photoelectricconversion portions, charge in first electrodes to the outside of thesystem, and then transferring, in all imaging elements all at once, thecharge accumulated in the photoelectric conversion portions to the firstelectrodes and sequentially reading out, after completion of thetransfer, the charge transferred to the first electrodes in the imagingelements.

In such a driving method for a solid-state image sensor as describedabove, since each imaging element is structured such that light incidentfrom the second electrode side is not incident to the first electrodeand, while charge is accumulated into the photoelectric conversionportions in all imaging elements all at once, the charge in the firstelectrodes is discharged to the outside of the system, resetting of thefirst electrode can be simultaneously performed with certainty in allimaging elements. Thereafter, the charge accumulated in thephotoelectric conversion portion is transferred to the first electrodesin all imaging elements all at once, and after completion of thetransfer, the charge transferred to the first electrode in each imagingelement is read out sequentially. Therefore, what is generally called aglobal shutter function can be implemented readily.

Embodiment 1

The embodiment 1 relates to a solid-state image sensor of the presentdisclosure, particularly to the solid-state image sensor of the firstconfiguration. An arrangement state of a charge accumulating electrodeand a first electrode in the solid-state image sensor of the embodiment1 is schematically depicted in FIG. 1A. Further, schematic partialsectional views of the solid-state image sensor of the embodiment 1 aredepicted in FIGS. 9 and 10A, and equivalent circuit diagrams of animaging element and a stacked type imaging element of the embodiment 1are depicted in FIGS. 11 and 12 , respectively. Further, a schematicarrangement diagram of a first electrode and a charge accumulatingelectrode and transistors configuring a control portion that configurethe imaging element of the embodiment 1 is depicted in FIG. 13 .Further, a state of potentials at various portions upon operation of theimaging element of the embodiment 1 is depicted in FIG. 14 . Anequivalent circuit diagram of the imaging element and the stacked typeimaging element of the embodiment 1 illustrating the portions of FIG. 14is depicted in FIG. 15A. A conceptual view of the solid-state imagesensor of the embodiment 1 is depicted in FIG. 16 .

Here, FIG. 9 is a schematic partial sectional view taken along a dashedline A-B-C depicted in FIG. 1A, and FIG. 10A is a schematic partialsectional view taken along a dashed line A-B-D-E depicted in FIG. 1A.Further, in order to simplify the drawings, various imaging elementcomponents positioned below an interlayer insulating layer hereinafterdescribed are sometimes depicted collectively by a reference numeral 91for the convenience of illustration.

The solid-state image sensor of the embodiment 1 includes a plurality ofimaging element blocks 10 each configured from a plurality of imagingelements 11. Each imaging element 11 includes a first electrode 21, acharge accumulating electrode 24 arranged in a spaced relation from thefirst electrode 21, a photoelectric conversion portion 23 contactingwith the first electrode 21 and formed above the charge accumulatingelectrode 24 with an insulating layer 82 interposed therebetween, and asecond electrode 22 formed on the photoelectric conversion portion 23.The first electrode 21 and the charge accumulating electrode 24 areprovided on an interlayer insulating layer 81. The first electrode 21 ofthe imaging element 11 is connected to a connection portion 63 providedin the interlayer insulating layer 81.

In the solid-state image sensor of the embodiment 1, the imaging elementblock 10 is configured from P×Q (where P≥2, Q≥1) imaging elementsincluding P imaging elements 11 along a first direction and Q imagingelements 11 along a second direction different from the first direction.In particular, in the solid-state image sensor of the embodiment 1, P=2and Q=1. In other words, the imaging element block 10 is configured fromtwo first imaging elements 11 arranged side by side along the firstdirection. The first electrode 21 that configures each of the twoimaging elements 11 along the first direction is connected to aconnection portion 63 provided in the interlayer insulating layer 81.The plurality of imaging element blocks 10 is arrayed in atwo-dimensional matrix in the first direction and the second direction,for example.

The imaging elements 11 are arranged line-symmetrically with respect toa boundary line BL extending in the second direction between an imagingelement 11 and another imaging element 11 configuring the imagingelement block 10. Further, in FIG. 1A, one imaging element block 10 isdepicted. The connection portion 63 is configured from a connection hole65 provided in the interlayer insulating layer 81 and connected to thefirst electrode 21 and a wiring portion 64 provided in the interlayerinsulating layer 81 and extending on an insulating film 75 from theconnection hole 65. The connection portion 63 is connected to a contacthole portion 61.

Further, the solid-state image sensor of the embodiment 1 includes astacked type imaging element including at least one imaging element 11of the embodiment 1. In particular, at least one lower imaging element13 or 15 is provided below the imaging element 11 of the embodiment 1,and the wavelength of light that is received by the imaging element 11and the wavelength of light that is received by the lower imagingelement 13 or 15 are different from each other. In this case, the twolower imaging elements 13 and 15 are stacked.

The second electrode 22 positioned on the light incidence side is madecommon to a plurality of imaging elements 11 except the imaging elementof the embodiment 5 hereinafter described. In other words, the secondelectrode 22 is what is generally called a solid electrode. Thephotoelectric conversion portion 23 is made common to the plurality ofimaging elements 11. In other words, a single layer photoelectricconversion portion 23 is formed for the plurality of imaging elements11.

The stacked type imaging element of the embodiment 1 includes at leastone imaging element 11 of the embodiment 1 (in particular, in theembodiment 1, one imaging element 11 of the embodiment 1).

The stacked type imaging element of the embodiment 1 further includes acontrol portion provided on a semiconductor substrate and including adriving circuit, and the first electrodes 21 of the two imaging elements11 configuring the imaging element block 10 are connected to the drivingcircuit through the connection portion 63 (particularly, the connectionhole 65 and the wiring portion 64) and the contact hole portion 61. Thesecond electrode 22 and the charge accumulating electrode 24 are alsoconnected to the driving circuit.

For example, the first electrode 21 is brought to a positive potentialwhile the second electrode 22 is brought to a negative potential suchthat electrons generated by photoelectric conversion in thephotoelectric conversion portion 23 are read out into a first floatingdiffusion layer FD₁. This similarly applies to the other embodiments aswell. In a form in which the first electrode 21 is brought to a positivepotential while the second electrode 22 is brought to a positivepotential such that positive holes generated on the basis ofphotoelectric conversion in the photoelectric conversion portion 23 areread out into the first floating diffusion layer FD₁, it is sufficientif the high and low potentials described below are reversed.

Moreover, the imaging element 11 of the embodiment 1 further includes acontrol portion provided on the semiconductor substrate 70 and includinga driving circuit. The first electrode 21 and the charge accumulatingelectrode 24 are connected to the driving circuit. During a chargeaccumulation period, from the driving circuit, a potential V₁₁ isapplied to the first electrode 21, a potential V₃₁ is applied to thecharge accumulating electrode 24, and charge is accumulated into thephotoelectric conversion portion 23. During a charge transfer period,from the driving circuit, a potential V₁₂ is applied to the firstelectrode 21, a potential V₃₂ is applied to the charge accumulatingelectrode 24, and charge accumulated in the photoelectric conversionportion 23 is read out into the control portion via the first electrode21. However, since the potential of the first electrode 21 is set higherthan the potential of the second electrode 22, V₃₁≥V₁₁ and V₃₂<V₁₂ aresatisfied.

In the following, operation of the stacked type imaging element (firstimaging element) that includes the charge accumulating electrode of theembodiment 1 is described with reference to FIGS. 14 and 15A. Here, thepotential of the first electrode 21 is set higher than the potential ofthe second electrode 22. In other words, the first electrode 21 isbrought to a positive potential and the second electrode 22 is broughtto a negative potential. Electrons generated by photoelectric conversionin the photoelectric conversion portion 23 are read out into thefloating diffusion layer. This similarly applies to the otherembodiments as well. It is to be noted that, in a form in which thefirst electrode 21 is brought to a negative potential and the secondelectrode 22 is brought to a positive potential such that positive holesgenerated on the basis of photoelectric conversion in the photoelectricconversion portion 23 are read out into the floating diffusion layer, itis sufficient if the high and low potentials described below arereversed.

Reference signs used in FIG. 14 and in FIGS. 32 and 33 in the embodiment8 hereinafter described are such as described below.

P_(A) . . . potential at a point P_(A) in a region of the photoelectricconversion portion 23 opposed to a region positioned intermediatelybetween the charge accumulating electrode 24 or the transfer controllingelectrode (charge transfer electrode) 25 and the first electrode 21

P_(B) . . . potential at a point P_(B) in a region of the photoelectricconversion portion 23 opposed to the charge accumulating electrode 24

P_(C) potential at a point P_(c) in a region of the photoelectricconversion portion 23 opposed to the transfer controlling electrode(charge transfer electrode) 25

FD potential at the first flowing diffusion layer FD₁

V_(0A) potential at the charge accumulating electrode 24

V_(OT) potential at the transfer controlling electrode (charge transferelectrode) 25

RST . . . potential at a gate portion 51 of a reset transistor TR1_(rst)

V_(DD) . . . potential of a power supply

VSL₁ . . . signal line (data output line) VSL₁

TR1 _(rst) . . . reset transistor TR1 _(rst)

TR1 _(amp) . . . amplification transistor TR1 _(amp)

TR1 _(sel) . . . selection transistor TR1 _(sel)

<Charge Accumulation Period>

During a charge accumulation period, from the driving circuit, thepotential V₁₁ is applied to the first electrode 21 and the potential V₃₁is applied to the charge accumulating electrode 24. Further, thepotential V₂₁ is applied to the second electrode 22. Thus, photoelectricconversion occurs in the photoelectric conversion portion 23 by lightincident to the photoelectric conversion portion 23, and charge(electrons) is accumulated into the photoelectric conversion portion 23.Positive holes generated by the photoelectric conversion are sent outfrom the second electrode 22 to the driving circuit through a wiringV_(OU). On the other hand, since the potential of the first electrode 21is set higher than the potential of the second electrode 22, that is,for example, a positive potential is applied to the first electrode 21and a negative potential is applied to the second electrode 22, V₃₁≥V₁₁,preferably, V₃₁>V₁₁, is satisfied. By this, electrons generated byphotoelectric conversion are attracted to the charge accumulatingelectrode 24 and stay in a region of the photoelectric conversionportion 23 opposed to the charge accumulating electrode 24. In otherwords, charge is accumulated into the photoelectric conversion portion23. Since V₃₁>V₁₁ is satisfied, electrons generated in the inside of thephotoelectric conversion portion 23 do not move toward the firstelectrode 21. As the time of photoelectric conversion elapses, thepotential in the region of the photoelectric conversion portion 23opposed to the charge accumulating electrode 24 comes to have anincreasing negative side value.

At a later stage of the charge accumulation period, a reset operation isperformed. Consequently, the potential of the first floating diffusionlayer FD₁ is reset, and the potential (V_(FD)) of the first floatingdiffusion layer FD₁ becomes equal to the potential V_(DD) of the powersupply.

<Charge Transfer Period>

After completion of the reset operation, reading out of charge isperformed. In other words, a charge transfer period is started. Duringthe charge transfer period, from the driving circuit, the potential V₁₂is applied to the first electrode 21 and the potential V₃₂ is applied tothe charge accumulating electrode 24. Further, the potential V₂₂ isapplied to the second electrode 22. Here, V₃₂<V₁₂ is assumed. Thus,charge accumulated in the photoelectric conversion portion 23 of theimaging element 11 is read out. In other words, electrons staying in theregion of the photoelectric conversion portion 23 opposed to the chargeaccumulating electrode 24 are read out to the first electrode 21 andfurther to the first floating diffusion layer FD₁. In other words, thecharge accumulated in the photoelectric conversion portion 23 is readout to the control portion.

With the above, the series of operations of charge accumulation, a resetoperation, and charge transfer is completed.

Operation of the amplification transistor TR1 _(amp) and the selectiontransistor TR1 _(sel) after electrons are read out into the firstfloating diffusion layer FD₁ is the same as operation of conventionalamplification transistor and selection transistor. Such a series ofoperations as charge accumulation, a reset operation, and chargetransfer of the second imaging element 13 and the third imaging element15 is similar to such a conventional series of operations as chargeaccumulation, a reset operation, and charge transfer. Reset noise of thefirst floating diffusion layer FD₁ can be removed by a correlated doublesampling (CDS) process similarly to the conventional technology.

The solid-state image sensor of the embodiment 1 further includes asemiconductor substrate (more particularly, silicon semiconductor layer)70, and the photoelectric conversion portion is arranged above thesemiconductor substrate 70. The solid-state image sensor of theembodiment 1 further includes a control portion that is provided on thesemiconductor substrate 70 and includes a driving circuit to which thefirst electrode 21, second electrode 22, and charge accumulatingelectrode 24 are connected. Here, the light incident face of thesemiconductor substrate 70 is the upper side and the opposite side ofthe semiconductor substrate 70 is the lower side. Below thesemiconductor substrate 70, a wiring layer 62 including a plurality ofwirings is provided.

On the semiconductor substrate 70, at least the floating diffusion layerFD₁ and the amplification transistor TR1 _(amp) that configure thecontrol portion are provided, and the first electrode 21 is connected tothe floating diffusion layer FD₁ and the gate portion of theamplification transistor TR1 _(amp). On the semiconductor substrate 70,the reset transistor TR1 _(rst) and the selection transistor TR1 _(sel)that configure the control portion are further provided. The floatingdiffusion layer FD₁ is connected to one of the source/drain regions ofthe reset transistor TR1 _(rst), the other one of the source/drainregions of the amplification transistor TR1 _(amp) is connected to theone of the source/drain regions of the selection transistor TR1 _(sel),and the other one of the source/drain regions of the selectiontransistor TR1 _(sel) is connected to a signal line VSL₁. Theamplification transistor TR1 _(amp), reset transistor TR1 _(rst), andselection transistor TR1 _(sel) configure the driving circuit.

Although, in the example depicted, a state in which one floatingdiffusion layer FD₁ and so forth are provided for two imaging elements11 is depicted, in embodiments hereinafter described, the floatingdiffusion layer FD₁ and so forth are shared by four imaging elements 11.

In particular, the imaging element and the stacked type imaging elementof the embodiment 1 are an imaging element and a stacked type imagingelement of the back-illuminated type, and are structured such that threeimaging elements 11, 13, and 15 are stacked including a green lightimaging element (hereinafter referred to as “first imaging element”) ofthe embodiment 1 of the first type that includes a green lightphotoelectric conversion portion of the first type that absorbs greenlight and has the sensitivity to green light, a conventional blue lightimaging element (hereinafter referred to as “second imaging element”) ofthe second type that includes a blue light photoelectric conversionportion of the second type that absorbs blue light and has thesensitivity to blue light, and a conventional red light imaging element(hereinafter referred to as “third imaging element”) of the second typethat includes a red light photoelectric conversion portion of the secondtype that absorbs red light and has the sensitivity to red light. Here,the red light imaging element (third imaging element) 15 and the bluelight imaging element (second imaging element) 13 are provided in thesemiconductor substrate 70 such that the second imaging element 13 ispositioned on the light incidence side with respect to the third imagingelement 15. Further, the green light imaging element (first imagingelement) 11 is provided above the blue light imaging element (secondimaging element) 13. One pixel is configured from a stacked structure ofthe first imaging element 11, the second imaging element 13, and thethird imaging element 15. No color filter is provided.

In the first imaging element 11, the connection portion (particularly,the connection hole 65 and the wiring portion 64) is formed in theinterlayer insulating layer 81, and the first electrode 21 and thecharge accumulating electrode 24 are formed in a spaced relation fromeach other on the interlayer insulating layer 81. The interlayerinsulating layer 81 and the charge accumulating electrode 24 are coveredwith the insulating layer 82. The photoelectric conversion portion 23 isformed on the insulating layer 82, and the second electrode 22 is formedon the photoelectric conversion portion 23. A protective layer 83 isformed over an overall area including the second electrode 22, and anon-chip microlens 90 is provided on the protective layer 83. The firstelectrode 21, the charge accumulating electrode 24, and the secondelectrode 22 are each configured, for example, from a transparentelectrode made of ITO (work function: approximately 4.4 eV). Thephotoelectric conversion portion 23 is configured from a photoelectricconversion layer and is configured from a layer that contains a knownorganic photoelectric conversion material at least having thesensitivity to green light (for example, a rhodamine pigment, amelacianin pigment, or an organic material such as quinacridone).Further, the photoelectric conversion portion 23 may be configured suchthat it further includes a material layer suitable for chargeaccumulation. In other words, a material layer suitable for chargeaccumulation may be further formed between the photoelectric conversionportion 23 and the first electrode 21 (for example, in a connectingportion 68). The interlayer insulating layer 81, the insulating layer82, and the protective layer 83 are configured from a known insulatingmaterial (for example, SiO₂ or SiN). The photoelectric conversionportion 23 and the first electrode 21 are connected to each other by theconnecting portion 68 provided on the insulating layer 82. In theconnecting portion 68, the photoelectric conversion portion 23 extends.In other words, the photoelectric conversion portion 23 extends in anopening 84 provided in the insulating layer 82 and is connected to thefirst electrode 21.

The charge accumulating electrode 24 is connected to the drivingcircuit. In particular, the charge accumulating electrode 24 isconnected to a vertical driving circuit 112, which configures thedriving circuit, through a connecting portion 67 provided in theinterlayer insulating layer 81, a pad portion 66, and a wiring V_(OA).

The size of the charge accumulating electrode 24 is greater than that ofthe first electrode 21. Where the area of the charge accumulatingelectrode 24 is presented by s₁′ and the area of the first electrode 21is represented by s₁, though not restrictive, it is preferable tosatisfy 4≤s₁′/s₁, and in the imaging element of the embodiment 1 or anyof the embodiments hereinafter described, for example, s₁′/s₁=8 issatisfied, though not restrictive.

An element isolation region 71 is formed on a first face (front face)70A side of the semiconductor substrate 70, and an oxide film 72 isformed on the first face 70A of the semiconductor substrate 70. Further,the reset transistor TR1 _(rst), amplification transistor TR1 _(amp),and selection transistor TR1 _(sel) that configure the control portionof the first imaging element 11 are provided on the first face side ofthe semiconductor substrate 70, and the first floating diffusion layerFD₁ is further provided.

The reset transistor TR1 _(rst) is configured from the gate portion 51,channel formation region 51A, and source/drain regions 51B and 51C. Thegate portion 51 of the reset transistor TR1 _(rst) is connected to thereset line RST₁, and the source/drain region 51C, which is one of thesource/drain regions of the reset transistor TR1 _(rst), doubles as thefirst floating diffusion layer FD₁, and the source/drain region 51B,which is the other one of the source/drain regions, is connected to thepower supply V_(DD).

The first electrode 21 is connected to the one source/drain region 51C(first floating diffusion layer FD₁) of the reset transistor TR1 _(rst)through the connection portion 63 (the connection hole 65 and the wiringportion 64) provided in the interlayer insulating layer 81, the contacthole portion 61 formed in the semiconductor substrate 70 and theinterlayer insulating film 76, and the wiring layer 62 formed on theinterlayer insulating film 76.

The amplification transistor TR1 _(amp) is configured from a gateportion 52, a channel formation region 52A, and source/drain regions 52Band 52C. The gate portion 52 is connected to the first electrode 21 andthe source/drain region 51C (first floating diffusion layer FD₁), whichis one of the source/drain regions of the reset transistor TR1 _(rst),through the wiring layer 62. Meanwhile, the source/drain region 52B,which is one of the source/drain regions, is connected to the powersupply V_(DD).

The selection transistor TR1 _(sel) is configured from a gate portion53, a channel formation region 53A, and source/drain regions 53B and53C. The gate portion 53 is connected to a selection line SEL₁. Further,the one source/drain region 53B shares a region with the othersource/drain region 52C configuring the amplification transistor TR1_(amp), and the other source/drain region 53C is connected to the signalline (data output line) VSL₁ (117).

The second imaging element 13 includes, as a photoelectric conversionlayer, an n-type semiconductor region (second photoelectric conversionportion) 41 provided on the semiconductor substrate 70. A gate portion45 of a transfer transistor TR2 _(trs) configured from a verticaltransistor extends to the n-type semiconductor region 41 and isconnected to a transfer gate line TG₂. Further, a second floatingdiffusion layer FD₂ is provided in a region 45C of the semiconductorsubstrate 70 in the proximity of the gate portion 45 of the transfertransistor TR2 _(trs). Charge accumulated in the n-type semiconductorregion 41 is read out to the second floating diffusion layer FD₂ througha transfer channel formed along the gate portion 45.

In the second imaging element 13, a reset transistor TR2 _(rst), anamplification transistor TR2 _(amp), and a selection transistor TR2_(sel) that configure a control portion of the second imaging element 13are further provided on the first face side of the semiconductorsubstrate 70.

The reset transistor TR2 _(rst) is configured from a gate portion, achannel formation region, and source/drain regions. The gate portion ofthe reset transistor TR2 _(rst) is connected to a reset line RST₂, andone of the source/drain regions of the reset transistor TR2 _(rst) isconnected to the power supply V_(DD) while the other one of thesource/drain regions doubles as the second floating diffusion layer FD₂.

The amplification transistor TR2 _(amp) is configured from a gateportion, a channel formation region, and source/drain regions. The gateportion is connected to the other one (second floating diffusion layerFD₂) of the source/drain regions of the reset transistor TR2 _(rst).Meanwhile, the one of the source/drain regions is connected to the powersupply V_(DD).

The selection transistor TR2 _(sel) is configured from a gate portion, achannel formation region, and source/drain regions. The gate portion isconnected to a selection line SEL₂. Meanwhile, one of the source/drainregions shares a region with the other one of the source/drain regionsconfiguring the amplification transistor TR2 _(amp), and the other oneof the source/drain regions is connected to a signal line (data outputline) VSL₂.

The third imaging element 15 includes, as a photoelectric conversionlayer, an n-type semiconductor region (third photoelectric conversionportion) 43 provided on the semiconductor substrate 70. A gate portion46 of a transfer transistor TR3 _(trs) is connected to a transfer gateline TG₃. Further, a third floating diffusion layer FD₃ is provided in aregion 46C of the semiconductor substrate 70 in the proximity of thegate portion 46 of the transfer transistor TR3 _(trs). Chargeaccumulated in the n-type semiconductor region 43 is read out to thethird floating diffusion layer FD₃ through a transfer channel 46A formedalong the gate portion 46.

In the third imaging element 15, a reset transistor TR3 _(rst), anamplification transistor TR3 _(amp), and a selection transistor TR3_(sel) configuring a control portion of the third imaging element 15 arefurther provided on the first face side of the semiconductor substrate70.

The reset transistor TR3 _(rst) is configured from a gate portion, achannel formation region, and source/drain regions. The gate portion ofthe reset transistor TR3 _(rst) is connected to a reset line RST₃, andone of the source/drain regions of the reset transistor TR3 _(rst) isconnected to the power supply V_(DD), and the other one of thesource/drain region doubles as the third floating diffusion layer FD₃.

The amplification transistor TR3 _(amp) is configured from a gateportion, a channel formation region, and source/drain regions. The gateportion is connected to the other one (third floating diffusion layerFDA of the source/drain regions of the reset transistor TR3 _(rst).Meanwhile, the one of the source/drain regions is connected to the powersupply V_(DD).

The selection transistor TR3 _(sel) is configured from a gate portion, achannel formation region, and source/drain regions. The gate portion isconnected to a selection line SEL₃. Meanwhile, one of the source/drainregions shares a region with the other one of the source/drain regionsconfiguring the amplification transistor TR3 _(amp), and the other oneof the source/drain regions is connected to a signal line (data outputline) VSL₃.

The reset lines RST₁, RST₂, and RST₃, selection lines SEL₁, SEL₂, andSEL₃, and transfer gate lines TG₂ and TG₃ are connected to the verticaldriving circuit 112 that configure the driving circuit, and the signallines (data output lines) VSL₁, VSL₂, and VSL₃ are connected to a columnsignal processing circuit 113 that configures the driving circuit.

A p⁺ layer 44 is provided between the n-type semiconductor region 43 andthe front face 70A of the semiconductor substrate 70 and suppressesgeneration of dark current. A p⁺ layer 42 is formed between the n-typesemiconductor region 41 and the n-type semiconductor region 43, and partof a side face of the n-type semiconductor region 43 is surrounded bythe p⁺ layer 42. A p⁺ layer 73 is formed on the side of the rear face70B of the semiconductor substrate 70, and an HfO₂ film 74 and theinsulating film 75 are formed at a portion at which the contact holeportion 61 in the inside of the semiconductor substrate 70 from the p⁺layer 73 is to be formed. Although wirings are formed in the interlayerinsulating film 76 over a plurality of layers, illustration of them isomitted.

The HfO₂ film 74 is a film having negative fixed charge, and generationof dark current can be suppressed by providing such a film as justdescribed. It is to be noted that it is also possible to use, in placeof a HfO₂ film, an aluminum oxide (Al₂O₃) film, a zirconium oxide (ZrO₂)film, a tantalum oxide (Ta₂O₅) film, a titanium oxide (TiO₂) film, alanthanum oxide (LA₂O₃) film, a praseodymium oxide (Pr₂O₃) film, acerium oxide (CeO₂) film, a neodymium oxide (Nd₂O₃) film, a promethiumoxide (Pm₂O₃) film, a samarium oxide (Sm₂O₃) film, a europium oxide(Eu₂O₃) film, a gadolinium oxide (Gd₂O₃) film, a terbium oxide (Tb₂O₃)film, a dysprosium oxide (Dy₂O₃) film, a holmium oxide (Ho₂O₃) film, athulium oxide (Tm₂O₃), an ytterbium oxide (Yb₂O₃) film, a lutetium oxide(Lu₂O₃) film, an yttrium oxide (Y₂O₃) film, a hafnium nitride film, analuminum nitride film, a hafnium oxynitride film, and an aluminumoxynitride film. As a film formation method of the films mentioned, forexample, a CVD method, a PVD method, and an ALD method can be listed.

FIG. 16 depicts a conceptual diagram of the solid-state image sensor ofthe embodiment 1. The solid-state image sensor 100 of the embodiment 1is configured from an imaging region 111 in which stacked type imagingelements 101 are arrayed in a two-dimensional array, the verticaldriving circuit 112, a column signal processing circuit 113, ahorizontal driving circuit 114, an outputting circuit 115, a drivingcontrolling circuit 116, and so forth as driving circuits (peripheralcircuits). Note that it is a matter of course that the circuits can beconfigured from known circuits and can be configured using other circuitconfigurations (for example, various circuits used in a conventional CCDtype solid-state image sensor or a conventional CMOS type solid-stateimage sensor). It is to be noted that the reference number “101” isapplied only for one row in the stacked type imaging elements 101 inFIG. 16 .

The driving controlling circuit 116 generates a clock signal thatservers as a reference for operation of the vertical driving circuit112, column signal processing circuit 113, and horizontal drivingcircuit 114 and control signals for them on the basis of a verticalsynchronizing signal, a horizontal driving signal, and a master clock.Then, the generated clock signal and control signals are inputted to thevertical driving circuit 112, column signal processing circuit 113, andhorizontal driving circuit 114.

The vertical driving circuit 112 is configured, for example, from ashift register and performs selection scanning of the stacked typeimaging elements 101 of the imaging region 111 sequentially in a unit ofa row in the vertical direction. Then, a pixel signal (image signal)based on current (signal) generated according to a light amount receivedby each stacked type imaging element 101 is sent to the column signalprocessing circuit 113 through a signal line (data output line) 117 anda VSL.

The column signal processing circuit 113 is arranged, for example, foreach column of the stacked type imaging elements 101 and performs signalprocessing such as noise removal or signal amplification for imagesignals outputted from the stacked type imaging elements 101 for one rowusing a signal from a black reference pixel (though not depicted, formedaround the effective pixel region) for each imaging element. At theoutput stage of the column signal processing circuit 113, a horizontalselection switch (not depicted) is provided in connection to ahorizontal signal line 118.

The horizontal driving circuit 114 is configured, for example, from ashift register and sequentially outputs a horizontal scanning pulse tosequentially select the column signal processing circuits 113 such thata signal is outputted from each of the column signal processing circuits113 to the horizontal signal line 118.

The outputting circuit 115 performs signal processing for signalssequentially supplied from the column signal processing circuits 113through the horizontal signal line 118 and outputs a resulting signal.

As indicated by FIG. 17 that depicts an equivalent circuit diagram of amodification (modification 1 of the embodiment 1) of the imaging elementand the stacked type imaging element of the embodiment 1 and FIG. 18that depicts a schematic arrangement diagram of the first electrodes andthe charge accumulating electrodes and transistors that configure thecontrol portion, the other source/drain region of the reset transistorTR1 _(rst) may be grounded in place of being connected to the powersupply V_(DD).

The imaging element and the stacked type imaging element of theembodiment 1 can be produced, for example, by the following method. Inother words, a SOI substrate is prepared first. Then, a first siliconlayer is formed on the surface of the SOI substrate by an epitaxialgrowth method, and the p⁺ layer 73 and the n-type semiconductor region41 are formed on the first silicon layer. Then, a second silicon layeris formed on the first silicon layer by an epitaxial grow method, andthe element isolation region 71, the oxide film 72, the p⁺ layer 42, then-type semiconductor region 43, and the p⁺ layer 44 are formed on thesecond silicon layer. Further, various transistors and so forth thatconfigure the control portions for the imaging elements are formed onthe second silicon layer, and the wiring layer 62, the interlayerinsulating film 76, and various wirings are formed on them, whereafterthe interlayer insulating film 76 and a support substrate (not depicted)are pasted together. Thereafter, the SOI substrate is removed to exposethe first silicon layer. It is to be noted that the surface of thesecond silicon layer corresponds to the front face 70A of thesemiconductor substrate 70, and the surface of the first silicon layercorresponds to the rear face 70B of the semiconductor substrate 70.Further, the first silicon layer and the second silicon layer arecollectively represented as semiconductor substrate 70. Then, on therear face 70B side of the semiconductor substrate 70, an opening forforming each contact hole portion 61 is formed, and the HfO₂ film 74,the insulating film 75, and the contact hole portion 61 are formed.Further, the wiring portion 64, the pad portion 66, the interlayerinsulating layer 81, the connection hole 65, the connecting portion 67,the first electrode 21, the charge accumulating electrode 24, and theinsulating layer 82 are formed. Then, the connecting portion 68 isopened, and the photoelectric conversion portion 23, the secondelectrode 22, the protective layer 83, and the on-chip microlens 90 areformed. By the foregoing, the solid-state image sensor of the embodiment1 can be obtained.

Alternatively, although a schematic partial sectional view of amodification of the imaging elements 11 of the embodiment 1 (two imagingelements placed side by side are illustrated) is depicted in FIG. 10B,the photoelectric conversion portion 23 can be structured in a stackedstructure of a lower layer semiconductor layer 23 _(DN) and an upperlayer photoelectric conversion layer 23 _(UP). The upper layerphotoelectric conversion layer 23 _(UP) is made common to the pluralityof imaging elements 11. In other words, in the plurality of imagingelements 11, the upper layer photoelectric conversion layer 23 _(UP) inthe form of one layer is formed. On the other hand, the lower layersemiconductor layer 23 _(DN) is provided in each of the imaging elements11. By providing the lower layer semiconductor layer 23 _(DN) in thismanner, for example, charge recombination upon charge accumulation canbe prevented. Further, the charge transfer efficiency of chargeaccumulated in the photoelectric conversion portion 23 to the firstelectrode 21 can be increased. Further, charge generated in thephotoelectric conversion portion 23 can be retained temporarily, and thetiming and so forth of transfer of the charge can be controlled.Further, generation of dark current can be suppressed. As regards thematerial for configuring the upper layer photoelectric conversion layer23 _(UP), it is sufficient if it is suitably selected from variousmaterials that configure the photoelectric conversion portion 23. On theother hand, as the material for configuring the lower layersemiconductor layer 23 _(DN), it is preferable to use a material that ishigh in band gap energy (for example, a value of the band gap energyequal to or higher than 3.0 eV) and besides is higher in mobility thanthe material configuring the upper layer photoelectric conversion layer23 _(UP), and particularly, for example, an oxide semiconductor materialsuch as IGZO can be listed. As an alternative, as a material forconfiguring the lower layer semiconductor layer 23 _(DN), in the casewhere charge to be accumulated is electrons, a material having a higherionization potential than that of the material configuring the upperlayer photoelectric conversion layer 23 _(UP) can be listed.Alternatively, the impurity concentration of a material configuring thelower semiconductor layer preferably is equal to or lower than 1×10¹⁸cm⁻³. It is to be noted that the configuration and the structure of themodification 2 of the embodiment 1 can be applied to the otherembodiments.

In the imaging element block of the solid-state image sensor of theembodiment 1, since the plurality of first electrodes is connected tothe connection portion provided in the interlayer insulating layer, thearrangement state of the first electrode, the charge accumulatingelectrode, and the photoelectric conversion portion that configure theimaging element can be made a same arrangement state with respect toincident light among the imaging elements of the imaging element block.As a result, no difference occurs in the state of movement, to the firstelectrodes, of charge generated in the imaging elements relying upon theangle of light incident to the imaging elements.

Besides, in the imaging elements of the embodiment 1 or an embodiment 2to an embodiment 9 hereinafter described, a charge accumulatingelectrode is provided which is arranged in a spaced relation from thefirst electrode and besides is arranged in an opposed relation to thephotoelectric conversion portion with an insulating layer interposedtherebetween. Therefore, when light is irradiated upon the photoelectricconversion portion and is photoelectrically converted by thephotoelectric conversion portion, a kind of capacitor is formed by thephotoelectric conversion portion, the insulating layer, and the chargeaccumulating electrode, and charge can be accumulated into thephotoelectric conversion portion. Therefore, it is possible uponstarting of exposure to completely deplete the charge accumulatingportion and erase charge. As a result, occurrence of such a phenomenoncan be suppressed that kTC noise increases and random noise gets worse,resulting in degradation of the imaged picture quality. Besides, sinceall pixels can be reset all at once, what is generally called a globalshutter function can be implemented.

Embodiment 2

The embodiment 2 is a modification of the embodiment 1. An arrangementstate of a charge accumulating electrode, a first electrode, and anisolation electrode (first isolation electrode) is schematicallydepicted in FIG. 1B, and a schematic partial sectional view is depictedin FIG. 19A. It is to be noted that FIG. 19A is a schematic partialsectional view taken along a dashed line A-B-C-D depicted in FIG. 1B. Inthe solid-state image sensor of the embodiment 2, the imaging elementblock 10 is surrounded by a continuous isolation electrode (firstisolation electrode 28). Further, as depicted in FIG. 2A that depicts anarrangement state of the charge accumulating electrode 24, the firstelectrode 21, the first isolation electrode 28, and a second isolationelectrode 29, the solid-state image sensor of the embodiment 2 can beconfigured such that the continuous second isolation electrode 29extending along the second direction from the first isolation electrode28 is provided between two imaging elements 11 along the firstdirection. The first isolation electrode 28 and the second isolationelectrode 29 are connected to each other. By providing the secondisolation electrode 29, charge generated by photoelectric conversion inthe imaging element 11 can be suppressed with certainty from flowinginto an adjacent imaging element in the imaging element block 10.Alternatively, as depicted in FIG. 2B that schematically depicts anarrangement state of the charge accumulating electrode 24, firstelectrode 21, and second isolation electrode 29, the solid-state imagesensor of the embodiment 2 can be configured such that the secondisolation electrode 29 extending along the second direction is providedbetween two imaging elements 11 along the first direction. It is to benoted that, in this case, the first isolation electrode 28 is notprovided. In the following description, the first isolation electrode 28and the second isolation electrode 29 are sometimes collectivelyreferred to as “isolation electrode 27.”

In FIGS. 2A, 2B, 4A, 4B, 6A, and 6B, illustration of the wiring portion64 is omitted.

Here, the first isolation electrode 28 is provided in a region opposedto a region of the photoelectric conversion portion 23 positionedbetween adjacent imaging elements 11 configuring adjacent imagingelement blocks 10 with an insulating layer 82 interposed therebetween.The first isolation electrode 28 is a lower first isolation electrode.Although the first isolation electrode 28 is formed at a level same asthat of the first electrode 21 or the charge accumulating electrode 24,it may otherwise be formed at a different level. Meanwhile, the secondisolation electrode 29 is provided, in the element block 10, in a regionopposed to a region of the photoelectric conversion portion 23positioned between adjacent imaging elements 11 configuring the imagingelement block 10 with the insulating layer 82 interposed therebetween.In other words, the second isolation electrode 29 is also a lower secondisolation electrode. Although the second isolation electrode 29 is alsoformed at a level same as that of the first electrode 21 or the chargeaccumulating electrode 24, it may otherwise be formed at a differentlevel. More particularly, the isolation electrode 27 is formed in aregion opposed to a region 23′ of the photoelectric conversion portion23 with the insulating layer 82 interposed therebetween (portion 82′ ofthe insulating layer). In other words, the isolation electrode 27 isformed under the portion 82′ of the insulating layer 82 in a regionsandwiched between a charge accumulating electrode 24 and another chargeaccumulating electrode 24 that individually configure adjacent imagingelements 11. The isolation electrode 27 is provided in a spaced relationfrom the charge accumulating electrode 24. Alternatively, in otherwords, the isolation electrode 27 is provided in a spaced relation fromthe charge accumulating electrode 24 and is arranged in an opposedrelation to the region 23′ of the photoelectric conversion portion 23with the insulating layer 82 interposed therebetween. This is alsoapplicable to the embodiment 3 and the embodiment 4 hereinafterdescribed.

Further, the potential of the isolation electrode (first isolationelectrode 28) (in a case where the second isolation electrode 29 isprovided, the potential of the second isolation electrode 29 also) has afixed value V_(ES). The isolation electrode 27 is connected to a drivingcircuit. In particular, the isolation electrode 27 is connected to avertical driving circuit 112, which configures the driving circuit,through a connecting portion 27A, a pad portion 27B, and a wiring (notdepicted) provided in the interlayer insulating layer 81. This can alsobe applied similarly to the embodiment 3 and the embodiment 4hereinafter described.

In the first imaging element 11, the first electrode 21 and the chargeaccumulating electrode 24 are formed in a spaced relation from eachother on the interlayer insulating layer 81. Further, the isolationelectrode 27 is formed in a spaced relation from the charge accumulatingelectrode 24 on the interlayer insulating layer 81. The interlayerinsulating layer 81, the charge accumulating electrode 24, and theisolation electrode 27 are covered with the insulating layer 82. Thephotoelectric conversion portion 23 is formed on the insulating layer82, and the second electrode 22 is formed on the photoelectricconversion portion 23. The protective layer 83 is formed over an overallarea including the second electrode 22, and the on-chip microlens 90 isprovided on the protective layer 83. The first electrode 21, the chargeaccumulating electrode 24, the isolation electrode 27, and the secondelectrode 22 are configured, for example, from a transparent electrodemade of ITO (work function: approximately 4.4 eV). This can also beapplied similarly to the embodiment 3 to the embodiment 4 hereinafterdescribed.

In the following, operation of the solid-state image sensor of theembodiment 2 is described.

<Charge Accumulation Period>

In particular, during a charge accumulation period, from the drivingcircuit, the potential V₁₁ is applied to the first electrode 21, thepotential V₃₁ is applied to the charge accumulating electrode 24, andthe potential V_(ES) is applied to the isolation electrode 27. Further,the potential V₂₁ is applied to the second electrode 22. Thus, charge(electrons) is accumulated into the photoelectric conversion portion 23.Electrons generated by photoelectric conversion are attracted to thecharge accumulating electrode 24 and stay in a region of thephotoelectric conversion portion 23 opposed to the charge accumulatingelectrode 24. In other words, charge is accumulated into thephotoelectric conversion portion 23. Since V₃₁>V₁₁ is satisfied,electrons generated in the inside of the photoelectric conversionportion 23 do not move toward the first electrode 21. Further, since thepotential V₃₁ of the charge accumulating electrode 24 is higher than thepotential V_(ES) of the isolation electrode 27, electrons generated inthe inside of the photoelectric conversion portion 23 do not move towardthe isolation electrode 27 either. In other words, electrons generatedby photoelectric conversion can be suppressed from flowing into anadjacent imaging element 11. As the time of photoelectric conversionelapses, the potential in the region of the photoelectric conversionportion 23 opposed to the charge accumulating electrode 24 has anincreasing negative side value. At a later stage of the chargeaccumulation period, a reset operation is performed. Consequently, thepotential of the first floating diffusion layer FD₁ is reset, and thepotential (V_(FD)) of the first floating diffusion layer FD₁ becomes thepotential V_(DD) of the power supply.

<Charge Transfer Period>

After completion of the reset operation, a charge transfer period isstarted. During the charge transfer period, from the driving circuit,the potential V₁₂ is applied to the first electrode 21, and thepotential V₃₂ is applied to the charge accumulating electrode 24.Further, the potential V_(ES) is applied to the isolation electrode 27.Electrons staying in the region of the photoelectric conversion portion23 opposed to the charge accumulating electrode 24 are read out to thefirst electrode 21 and further to the first floating diffusion layerFD₁. In other words, the charge accumulated in the photoelectricconversion portion 23 is read out to the control portion. The potentialof the isolation electrode 27 is lower than the potential of the firstelectrode 21 and is lower than the potential of the charge accumulatingelectrode 24. In other words, V_(ES)<V₃₂<V₁₂ is satisfied. Accordingly,electrons generated in the inside of the photoelectric conversionportion 23 flows to the first electrode 21 and do not move toward theisolation electrode 27. In other words, electrons generated byphotoelectric conversion can be suppressed from flowing to an adjacentimaging element 11.

Such a series of operations as charge accumulation, a reset operation,and charge transfer is completed therewith.

In the embodiment 2, since the isolation electrode 27 is provided,charge generated by photoelectric conversion can be suppressed withcertainty from flowing into an adjacent imaging element 11.

As depicted in FIG. 19B that is a schematic partial sectional view of amodification of the imaging elements 11 of the embodiment 2 (two imagingelements 11 placed side by side are illustrated), the photoelectricconversion portion 23 can be made in a stacked structure of the lowerlayer semiconductor layer 23 _(DN) and the upper layer photoelectricconversion layer 23 _(UP) similarly as in the modification of thesolid-state image sensor of the embodiment 1 depicted in FIG. 10B.

Embodiment 3

Although the embodiment 3 is a modification of the embodiment 1 and theembodiment 2, it relates to a solid-state image sensor of the secondconfiguration. As depicted in FIG. 3A that schematically depicts anarrangement state of the charge accumulating electrode 24 and the firstelectrode 21, in the solid-state image sensor of the embodiment 3, P=2is satisfied and Q is a natural number equal to or greater than 2.Although Q=2 is satisfied in the exampled depicted, this is notrestrictive. Further, the first electrode 21 that configures each of thetwo imaging elements 11 along the first direction is connected to theconnection portion 63 provided in the interlayer insulating layer 81.The connection portion 63 is connected to the contact hole portion 61.In the P×Q imaging elements 11, the first electrodes 21 are connected toeach other through the connection portion 63. Alternatively, as depictedin FIG. 3B that schematically depicts an arrangement state of the chargeaccumulating electrode 24, the first electrode 21, and the isolationelectrode (first isolation electrode) 28, in the modification of thesolid-state image sensor of the embodiment 3, the imaging element block10 is surrounded by a continuous isolation electrode (first isolationelectrode) 28. Further, as depicted in FIG. 4A that schematicallydepicts an arrangement state of the charge accumulating electrode 24,the first electrode 21, the first isolation electrode 28, and the secondisolation electrode 29, the solid-state image sensor can be configuredsuch that the continuous second isolation electrode 29 extending alongthe second direction from the first isolation electrode 28 is providedbetween two imaging elements 11 along the first direction. The firstisolation electrode 28 and the second isolation electrode 29 areconnected to each other. By providing the second isolation electrode 29,inflow of charge generated by photoelectric conversion between adjacentimaging elements 11 in the imaging element block 10 can be suppressedwith certainty. Alternatively, as depicted in FIG. 4B that schematicallydepicts an arrangement state of the charge accumulating electrode 24,the first electrode 21, and the second isolation electrode 29, thesolid-state image sensor can be configured such that the secondisolation electrode 29 extending along the second direction is providedbetween two imaging elements 11 along the first direction. It is to benoted that, in this case, the first isolation electrode 28 is notprovided.

Since operation of the solid-state image sensor of the embodiment 3 canbe made similar to the operation of the solid-state image sensorsdescribed hereinabove in connection with the embodiment 1 and theembodiment 2, detailed description of the operation is omitted.

Embodiment 4

Although the embodiment 4 is also a modification of the embodiment 1 andthe embodiment 2, it relates to a solid-state image sensor of the 3Athconfiguration and a solid-state image sensor of the 3Bth configuration.As depicted in FIG. 5A that schematically depicts an arrangement stateof the charge accumulating electrode 24 and the first electrode 21, P=2and Q=2 are satisfied, and the first electrode 21 configuring twoimaging elements 11 along the second direction is shared, and the sharedfirst electrode 21 is connected to the connection portion 63 provided inthe interlayer insulating layer 81. Alternatively, as depicted in FIG.7A that schematically depicts an arrangement state of the chargeaccumulating electrode 24 and the first electrode 21, P=2 and Q=2 aresatisfied, and the first electrode 21 configuring two imaging elements11 along the first direction is shared, and the shared first electrode21 is connected to the connection portion 63 provided in the interlayerinsulating layer 81. The connection portion 63 is connected to thecontact hole portion 61. In 2×2 imaging elements 11, the firstelectrodes 21 are connected to each other through the connection portion63. However, in this solid-state image sensor of the 3Bth configuration,also it is possible to make the value of Q a natural number equal to orgreater than 2 (for example, Q=4).

Alternatively, as depicted in FIGS. 5B and 7B that schematically depictarrangement states of the charge accumulating electrode 24, the firstelectrode 21, and the first isolation electrode (first isolationelectrode) 28, in the modification of the solid-state image sensor ofthe embodiment 4, the imaging element block 10 is surrounded by thecontinuous isolation electrode (first isolation electrode) 28. Further,as depicted in FIG. 6A that schematically depicts an arrangement stateof the charge accumulating electrode 24, the first electrode 21, thefirst isolation electrode 28, and the second isolation electrode 29, thesolid-state image sensor can be configured such that the continuoussecond isolation electrode 29 extending along the second direction fromthe first isolation electrode 28 is provided between two imagingelements 11 along the first direction. The first isolation electrode 28and the second isolation electrode 29 are connected to each other. Byproviding the second isolation electrode 29, charge generated byphotoelectric conversion in an adjacent imaging element 11 in theimaging element block 10 can be suppressed from flowing in withcertainty. Alternatively, as depicted in FIG. 6B that schematicallydepicts an arrangement state of the charge accumulating electrode 24,the first electrode 21, and the second isolation electrode 29, thesolid-state image sensor can be configured such that the secondisolation electrode 29 extending along the second direction is providedbetween two imaging elements 11 along the first direction. It is to benoted that, in this case, the first isolation electrode 28 is notprovided. The structure of the second isolation electrode 29 depicted inFIGS. 6A and 6B can be applied to the solid-state image sensor depictedin FIG. 7B.

Since operation of the solid-state image sensor of the embodiment 4 canbe made similar to the operation of the solid-state image sensorsdescribed hereinabove in connection with the embodiment 1 and theembodiment 2, detailed description of the operation is omitted.

A schematic perspective view of a modification of the solid-state imagesensor of the embodiment 4 depicted in FIG. 6A is depicted in FIG. 8A,and a schematic perspective view of a modification of the conventionalsolid-state image sensor is depicted in FIG. 8B.

As depicted in FIGS. 2A, 2B, 4A, 6B, 6A, and 6B of the embodiment 1, inthe solid-state image sensors of the embodiment 1 to the embodiment 4,the second isolation electrode 29 is continuous. In other words, thesecond isolation electrode 29 has no end portion.

On the other hand, a case is supposed in which, in the conventionalsolid-state image sensor, one imaging element block is configured fromfour imaging elements and one first electrode 21′ is shared by the fourimaging elements, for example. In this case, as depicted in FIG. 8B, itis necessary to provide the first electrode 21′ in a region in whichcorner portions of charge accumulating electrodes 24′ individuallyconfiguring the four imaging elements gather. Further, in a case where asecond isolation electrode 29′ corresponding to the second isolationelectrode 29 in the present disclosure is provided among four imagingelements, it is necessary to provide the second isolation electrode 29′in a spaced relation from the first electrode 21′ such that the secondisolation electrode 29′ and the first electrode 21′ do not contact witheach other. In other words, an end portion 29″ is inevitably formed onthe second isolation electrode 29′. The potential generated by thesecond isolation electrode 29′ having the end portion 29″ formed thereonin this manner, the charge accumulating electrode 24, and the firstelectrode 21′ has a complicated potential gradient due to the presenceof the end portion 29″ of the second isolation electrode 29′.Accordingly, a state in which charge generated in the photoelectricconversion portion 23 by photoelectric conversion and accumulated in thephotoelectric conversion portion 23 does not flow, upon charge transfer,appropriately and with certainty from the photoelectric conversionportion 23 to the first electrode 21′. In particular, the presence ofthe end portion 29″ of the second isolation electrode 29′ can give riseto a problem that the amount of charge to be accumulated into thephotoelectric conversion portion 23 decreases or, upon charge transfer,charge flows into the first electrode 21′ of an adjacent imagingelement. As a result, there is a possibility that degradation of thereliability of the solid-state image sensor may occur and the resolutionmay decrease.

However, in the solid-state image sensor of the present disclosure,since the second isolation electrode 29 does not have any end portion,the potentials generated by the second isolation electrode 29, thecharge accumulating electrode 24, and the first electrode 21 do not havea complicated potential gradient and can flow charge generated byphotoelectric conversion appropriately and with certainty from thephotoelectric conversion portion 23 to the first electrode 21.Accordingly, occurrence of degradation of the reliability anddegradation of the resolution of the solid-state image sensor can besuppressed.

Further, when attention is paid to the first electrode 21′ and thecharge accumulating electrode 24′, while an arrangement state of thefirst electrode and so forth of the conventional solid-state imagesensor for illustrating a first problem is schematically depicted inFIG. 43 , a case is assumed that light is incident from an obliquelyupper left portion of FIG. 43 . Here, if regions “A,” “B,” “C,” and “D,”of the photoelectric conversion portion, positioned above the chargeaccumulating electrodes 24′₁, 24′₂, 24′₃, and 24′₄ are examined, thenduring a charge accumulation period, part of charge generated in theregion “A” flows into the first electrode 21′ because the region “A” isadjacent the first electrode 21′. On the other hand, charge generated inthe region “B” and the region “C” is less likely to flow into the firstelectrode 21′ because the region “B” and the region “C” are not adjacentthe first electrode 21′. As a result of the foregoing, there is apossibility of the signal output of the imaging element that includesthe charge accumulating electrode 24′₁ may become lower than the signaloutputs of the imaging elements that include the charge accumulatingelectrodes 24′₂, 24′₃, and 24′₄. In other words, a state in which signaloutputs generated by the imaging elements become non-uniform occursdepending upon the incidence state of light.

On the other hand, for example, in the solid-state image sensor of theembodiment 3 depicted in FIGS. 3A, 3B, 4A, and 4B, even in a case wherelight is incident from an oblique upper left portion in FIGS. 3A, 3B,4A, and 4B, since the incident direction of light incident to the firstelectrode 21 and the charge accumulating electrode 24 is the same in thefour imaging elements, a non-uniform state is less likely to occur insignal outputs generated by the four imaging elements depending upon theincidence state of light, and this is apparent also from FIGS. 3A, 3B,4A, and 4B. In the other embodiments as well, it is similar that a statein which signal outputs generated are non-uniform is less likely tooccur in a plurality of imaging elements in which the arrangement of thecharge accumulating electrode 24 and the first electrode 21 configuringthe imaging element with respect to the incident state of light is thesame. As above, since, in one imaging element block, the plurality offirst electrodes 21 is connected to the connection portion 63 providedin the interlayer insulating layer 81 and the arrangement state of thefirst electrode 21, the photoelectric conversion portion 23, and thecharge accumulating electrode 24 can be made same as an arrangementstate with respect to incident light, the incidence direction of lightincident to the first electrode 21 and the charge accumulating electrode24 can be made same. Thus, a state in which signal outputs generated inimaging elements become non-uniform depending upon the angle of lightincident to the imaging elements can be suppressed from occurring as faras possible.

Embodiment 5

The embodiment 5 is a modification of the embodiment 1 to the embodiment4, and an upper isolation electrode 27′ (an upper first isolationelectrode, an upper first isolation electrode and upper second isolationelectrode, or an upper second isolation electrode) is provided in placeof the lower isolation electrode. A schematic sectional view of part ofthe imaging elements (two imaging elements placed side by side) of theembodiment 5 is depicted in FIG. 20 . In the imaging element of theembodiment 5, on a region 23 _(A) of the photoelectric conversionportion 23 positioned between adjacent imaging elements, the upperisolation electrode 27′ is formed in place of the second electrode 22.The upper isolation electrode 27′ is provided in a spaced relation fromthe second electrode 22. In other words, the second electrode 22 isprovided for each imaging element, and the upper isolation electrode 27′is provided on the region-A of the photoelectric conversion portion 23in a spaced relation from the second electrode 22 while surrounding atleast part of the second electrode 22. The upper isolation electrode 27′is formed in a level same as that of the second electrode 22.

Further, as depicted in FIG. 21A that depicts a schematic sectional viewof part of the imaging elements (two imaging elements placed side byside) of the embodiment 5, the second electrode 22 may be divided into aplurality of pieces such that potentials different from each other areindividually applied to the divided second electrodes 22. Furthermore,as depicted in FIG. 21B, the upper isolation electrode 27′ may beprovided between divided second electrodes 22.

The second electrode 22 and the upper isolation electrode 27′ can beobtained by forming a material layer for configuring the secondelectrode 22 and the upper isolation electrode 27′ on the photoelectricconversion portion 23 and then patterning the material layer. The secondelectrode 22 and the upper isolation electrode 27′ are individuallyconnected to different wirings (not depicted), and the wirings areconnected to a driving circuit. The wiring connected to the secondelectrode 22 is made common to a plurality of imaging elements. Thewiring connected to the upper isolation electrode 27′ is also madecommon to a plurality of imaging elements.

In the imaging element of the embodiment 5, during a charge accumulationperiod, from the driving circuit, the potential V₂₁ is applied to thesecond electrode 22 and the potential V_(ES) is applied to the upperisolation electrode 27′, and charge is accumulated into thephotoelectric conversion portion 23. During a charge transfer period,from the driving circuit, the potential V₂₂ is applied to the secondelectrode 22 and the potential V_(ES) is applied to the upper isolationelectrode 27′, and charge accumulated in the photoelectric conversionportion 23 is read out to the control section through the firstelectrode 21. Here, since the potential of the first electrode 21 is sethigher than the potential of the second electrode 22, V₂₁≥V_(ES) andV₂₂≥V_(ES) are satisfied.

As described above, in the imaging element of the embodiment 5, since,on the region of the photoelectric conversion portion positioned betweenadjacent imaging elements, the upper isolation electrode is formed inplace of the second electrode, charge generated by photoelectricconversion can be suppressed from flowing into an adjacent imagingelement by the upper isolation electrode. Therefore, quality degradationdoes not occur with a captured video (image).

A schematic sectional view of part of a modification of the imagingelements (two imaging elements placed side by side) of the embodiment 5is depicted in FIG. 22A. In this modification, the second electrode 22is provided for each imaging element, and the upper isolation electrode27′ is provided in a spaced relation from the second electrode 22 whilesurrounding at least part of the second electrode 22. Below the upperisolation electrode 27′, part of the charge accumulating electrode 24exists. The second electrode 22 is provided with a size smaller than thecharge accumulating electrode 24 above the charge accumulating electrode24. Further, in the example depicted in FIG. 22B, the lower isolationelectrode 27 is provided additionally below the upper isolationelectrode 27′. The size of the second electrode 22 is smaller than thatof the modification depicted in FIG. 22A. In other words, the region ofthe second electrode 22 opposed to the upper isolation electrode 27′ ispositioned on the first electrode 21 side with respect to the region ofthe second electrode 22 opposed to the upper isolation electrode 27′ inthe modification depicted in FIG. 22A. The charge accumulating electrode24 is surrounded by the lower isolation electrode 27.

Embodiment 6

The embodiment 6 is a modification of the embodiment 1 to the embodiment5. The solid-state image sensor of the embodiment 6 whose schematicpartial sectional view is depicted in FIG. 23 is a solid-state imagesensor of the front-illuminated type. In particular, the solid-stateimage sensor is structured such that the green light imaging element ofthe embodiment 1 of the first type (first imaging element) that includesa green light photoelectric conversion portion of the first type thatabsorbs green light and has the sensitivity to green light, aconventional blue light imaging element of the second type (secondimaging element) that includes a blue light photoelectric conversionportion of the second type that absorbs blue light and has thesensitivity to blue light, and a conventional red light imaging elementof the second type (third imaging element) that includes a red lightphotoelectric conversion portion of the second type that absorbs redlight and has the sensitivity to red light are stacked. Here, the redlight imaging element (third imaging element) and the blue light imagingelement (second imaging element) are provided in the semiconductorsubstrate 70 such that the second imaging element is positioned on thelight incidence side with respect to the third imaging element. Further,the green light imaging element (first imaging element) is providedabove the blue light imaging element (second imaging element).

On the front face 70A side of the semiconductor substrate 70, varioustransistors configuring a control portion are provided similarly as inthe embodiment 1. The transistors can be configured and structuredsubstantially similarly to the transistors described hereinabove inconnection with the embodiment 1. Further, although, on thesemiconductor substrate 70, the second imaging element and the thirdimaging element are provided, those imaging elements can also beconfigured and structured substantially similarly to the second imagingelement and the third imaging element described hereinabove inconnection with the embodiment 1.

Above the front face 70A of the semiconductor substrate 70, theinterlayer insulating layer 81 is formed, and in the interlayerinsulating layer 81, the first electrode 21, the photoelectricconversion portion 23, and the second electrode 22 as well as, asoccasion demands, isolation electrodes 27 and 27′, are providedsimilarly to in the imaging element of the solid-state image sensor ofthe embodiment 1 to the embodiment 5.

In this manner, since, except that the solid-state image sensor is ofthe front-illuminated type, the configuration and the structure of thesolid-state image sensor of the embodiment 6 can be made similar to theconfiguration and the structure of the solid-state image sensors of theembodiment 1 to the embodiment 5, detailed description of them isomitted.

Embodiment 7

The embodiment 7 is a modification of the embodiment 1 to the embodiment6.

The solid-state image sensor of the embodiment 7 whose schematic partialsectional view is depicted in FIG. 24 is a solid-state image sensor ofthe back-illuminated type and is structured such that two imagingelements, which are the first imaging element of the embodiment 1 of thefirst type and the second imaging element of the second type, arestacked. Further, a modification of the solid-state image sensor of theembodiment 7 whose schematic partial sectional view is depicted in FIG.25 is a solid-state image sensor of the front-illuminated type and isstructured such that two imaging elements, which are the first imagingelement of the embodiment 1 of the first type and the second imagingelement of the second type are stacked. Here, the first imaging elementabsorbs light of a primary color, and the second imaging element absorbslight of a complementary color. Alternatively, the first imaging elementabsorbs white light, and the second imaging element absorbs infraredlight.

A modification of the imaging element of the embodiment 7 whoseschematic partial sectional view is depicted in FIG. 26 is a solid-stateimage sensor of the back-illuminated type and is configured from thefirst imaging element of the embodiment 1 of the first type. Meanwhile,a modification of the solid-state image sensor of the embodiment 7 whoseschematic partial sectional view is depicted in FIG. 27 is a solid-stateimage sensor of the front-illuminated type and is configured from afirst imaging element of the embodiment 1 of the first type. Here, thefirst imaging element is configured from three different imagingelements including an imaging element that absorbs red light, anotherimaging element that absorbs green light, and a still another imagingelement that absorbs blue light. As arrangement of a plurality of suchimaging elements, a Bayer array can be listed. On the light incidenceside of each imaging element, color filters for spectral separation intoblue, green, and red are arranged as occasion demands.

Since, except the foregoing, the configuration and the structure of thesolid-state image sensor of the embodiment 7 can be made similar to theconfiguration and the structure of the solid-state image sensors of theembodiment 1 to the embodiment 5, detailed description of them isomitted. It is to be noted that the interlayer insulating layer 81 isformed above the front face 70A of the semiconductor substrate 70, andthe first electrode 21, the photoelectric conversion portion 23, and thesecond electrode 22 as well as, as occasion demands, the isolationelectrodes 27 and 27′ are provided in the interlayer insulating layer 81similarly to the imaging element of the solid-state image sensors of theembodiment 1 to the embodiment 5.

It is also possible to use a form in which, in place of providing oneimaging element of the embodiment 1 of the first type, two such imagingelements are stacked (that is, a form in which two photoelectricconversion portions are stacked and a control portion of the twophotoelectric conversion portions are provided on a semiconductorsubstrate) or use another form in which three such imaging elements arestacked (that is, a form in which three photoelectric conversionportions are stacked and a control portion of the three photoelectricconversion portions are provided on a semiconductor substrate). Examplesof the stacked structure of an imaging element of the first type and animaging element of the second type are exemplified in the followingtable.

First type Second type Back- 1 2 illuminated Green Blue + red type and 11 front- Primary color Complementary color illuminated 1 1 type WhiteInfrared rays 1 0 Blue, green, or red 2 2 Green + infrared Blue + redlight 2 1 Green + blue Red 2 0 White + infrared light 3 2 Green + blue +red Blue-green (emerald color) + infrared light 3 1 Green + blue + redInfrared light 3 0 Blue + green + red

Embodiment 8

The embodiment 8 is a modification of the embodiment 1 to the embodiment7 and relates to a solid-state image sensor that includes a transfercontrolling electrode (charge transfer electrode) of the presentdisclosure. A schematic partial sectional view of part of thesolid-state image sensor of the embodiment 8 is depicted in FIG. 28 ,and equivalent circuit diagrams of the solid-state image sensor of theembodiment 8 are depicted in FIGS. 29 and 30 . Further, a schematicarrangement diagram of a first electrode, a transfer controllingelectrode, and a charge accumulating electrode, and transistorsconfiguring a control portion which configure an imaging element of thesolid-state image sensor of the embodiment 8 is depicted in FIG. 31 .Further, states of potentials at individual portions upon operation ofthe imaging element of the embodiment 8 are depicted in FIGS. 32 and 33. Furthermore, an equivalent circuit diagram illustrating portions ofthe imaging element of the embodiment 8 is depicted in FIG. 15B.

The solid-state image sensor of the embodiment 8 further includes atransfer controlling electrode (charge transfer electrode) 25 arrangedin a spaced relation from the first electrode 21 and the chargeaccumulating electrode 24 between the first electrode 21 and the chargeaccumulating electrode 24 and besides arranged in an opposed relation tothe photoelectric conversion portion 23 with the insulating layer 82interposed therebetween. The transfer controlling electrode 25 isconnected to a pixel driving circuit configuring the driving circuitthrough a connecting portion 25B, a pad portion 25A, and a wiring V_(OT)provided in the interlayer insulating layer 81.

In the following, operation of the imaging element (first imagingelement) of the embodiment 8 is described with reference to FIGS. 32 and33 . It is to be noted that, in FIGS. 32 and 33 , the values of thepotential applied to the charge accumulating electrode 24 and thepotential at a point P_(C) are different.

During a charge accumulation period, from the driving circuit, thepotential V₁₁ is applied to the first electrode 21, the potential V₃₁ isapplied to the charge accumulating electrode 24, and the potential V₄₁is applied to the transfer controlling electrode 25. Photoelectricconversion takes place in the photoelectric conversion portion 23 bylight incident to the photoelectric conversion portion 23. Positiveholes generated by the photoelectric conversion are sent out from thesecond electrode 22 to the driving circuit through a wiring V_(OU). Onthe other hand, since the potential of the first electrode 21 is sethigher than the potential of the second electrode 22, that is, since,for example, a positive potential is applied to the first electrode 21and a negative potential is applied to the second electrode 22, V₃₁>V₄₁(for example, V₃₁>V₁₁>V₄₁ or V₁₁>V₃₁>V₄₁) is satisfied. Consequently,electrons generated by the photoelectric conversion are attracted to thecharge accumulating electrode 24 and stop in the region of thephotoelectric conversion portion 23 opposed to the charge accumulatingelectrode 24. In other words, charge is accumulated into thephotoelectric conversion portion 23. Since V₃₁>V₄₁ is satisfied,electrons generated in the inside of the photoelectric conversionportion 23 can be prevented with certainty from moving toward the firstelectrode 21. As time of the photoelectric conversion elapses, the valueof the potential in the region of the photoelectric conversion portion23 opposed to the charge accumulating electrode 24 increases in thenegative direction.

At a later stage of the charge accumulation period, a reset operation isperformed. Consequently, the potential of the first floating diffusionlayer FD₁ is reset, and the potential of the first floating diffusionlayer FD₁ becomes the potential V_(DD) of the power supply.

After completion of the reset operation, reading out of the charge isperformed. In other words, during a charge transfer period, from thedriving circuit, the potential V₁₂ is applied to the first electrode 21,the potential V₃₂ is applied to the charge accumulating electrode 24,and the potential V₄₂ is applied to the transfer controlling electrode25. Here, it is assumed that V₃₂≤V₄₂≤V₁₂ is satisfied (preferably,V₃₂<V₄₂<V₁₂ is satisfied). By this, electrons staying in the region ofthe photoelectric conversion portion 23 opposed to the chargeaccumulating electrode 24 are read out with certainty to the firstelectrode 21 and further to the first floating diffusion layer FD₁. Inother words, charge accumulated in the photoelectric conversion portion23 is read out to the control portion.

With the above, the series operation of charge accumulation, a resetoperation, and charge transfer is completed.

Operation of the amplification transistor TR1 _(amp) and the selectiontransistor TR1 _(sel) after electrons are read out into the firstfloating diffusion layer FD₁ is the same as operation of conventionalamplification transistor and selection transistor. Further, for example,such a series of operations as charge accumulation, a reset operation,and charge transfer of the second imaging element and the third imagingelement is similar to a conventional series of operations of chargetransfer, a reset operation, and charge transfer.

As depicted in FIG. 34 that depicts a schematic arrangement diagram of afirst electrode and a charge accumulating electrode and transistorsconfiguring a control portion which configure a modification of theimaging element of the embodiment 8, the other source/drain region 51Bof the reset transistor TR1 _(rst) may be grounded in place of beingconnected to the power supply V_(DD).

Further, a plurality of transfer controlling electrodes may be providedfrom a position nearest to the first electrode 21 toward the chargeaccumulating electrode 24.

Embodiment 9

The embodiment 9 is a modification of the embodiment 1 to the embodiment8 and relates to an imaging element and so forth that include a chargedischarging electrode of the present disclosure. A schematic partialsectional view of part of the imaging element of the embodiment 9 isdepicted in FIG. 35 .

The imaging element of the embodiment 9 further includes a chargedischarging electrode 26 connected to the photoelectric conversionportion 23 through a connecting portion 26A and arranged in a spacedrelation from the first electrode 21 and the charge accumulatingelectrode 24. Here, the charge discharging electrode 26 is arranged soas to surround the first electrode 21 and the charge accumulatingelectrode 24 (that is, in the form of a picture frame). The chargedischarging electrode 26 is connected to a pixel driving circuit thatconfigures the driving circuit. The photoelectric conversion portion 23extends in the connecting portion 26A. In other words, the photoelectricconversion portion 23 extends in a second opening 85 provided in theinsulating layer 82 and is connected to the charge discharging electrode26. The charge discharging electrode 26 is shared by (made common to) aplurality of imaging elements. The charge discharging electrode 26 canbe used, for example, as a floating diffusion or an overflow drain ofthe photoelectric conversion portion 23. In a case where it is difficultto provide the charge discharging electrode 26 and the lower isolationelectrode 27 at the same time, it is sufficient if the upper isolationelectrode 27′ is provided.

In the embodiment 9, during a charge accumulation period, from thedriving circuit, the potential V₁₁ is applied to the first electrode 21,the potential V₃₁ is applied to the charge accumulating electrode 24,and the potential V₅₁ is applied to the charge discharging electrode 26,and charge is accumulated into the photoelectric conversion portion 23.Photoelectric conversion takes place in the photoelectric conversionportion 23 by light incident to the photoelectric conversion portion 23.Positive holes generated by the photoelectric conversion are sent outfrom the second electrode 22 to the driving circuit through a wiringV_(OU). On the other hand, since the potential of the first electrode 21is set higher than the potential of the second electrode 22, that is,for example, since a positive potential is applied to the firstelectrode 21 and a negative potential is applied to the second electrode22, V₅₁≥V₁₁ (for example, V_(31>)≤V_(51>)≤V_(II)), is satisfied. Bythis, electrons generated by photoelectric conversion are attracted tothe charge accumulating electrode 24 and stay in a region of thephotoelectric conversion portion 23 opposed to the charge accumulatingelectrode 24, and can be prevented from moving toward the firstelectrode 21 with certainty. However, if the attraction by the chargeaccumulating electrode 24 is not sufficient or electrons remain withoutbeing accumulated into the photoelectric conversion portion 23 (what aregenerally called overflowing electrons), then the electrons are sent outto the driving circuit through the charge discharging electrode 26.

At a later stage of the charge accumulation period, a reset operation isperformed. Consequently, the potential of the first floating diffusionlayer FD₁ is reset, and the potential of the first floating diffusionlayer FD₁ becomes the potential V_(DD) of the power supply.

After completion of the reset operation, reading out of charge isperformed. In other words, during a charge transfer period, from thedriving circuit, the potential V₁₂ is applied to the first electrode 21,the potential V₃₂ is applied to the charge accumulating electrode 24,and the potential V₅₂ is applied to the charge discharging electrode 26.Here, V₅₂<V₁₂ (for example, V₅₂<V₃₂<V₁₂) is set. By this, electronsstaying in the region of the photoelectric conversion portion 23 opposedto the charge accumulating electrode 24 are read out to the firstelectrode 21 and further to the first floating diffusion layer FD₁ withcertainty. In other words, the charge accumulated in the photoelectricconversion portion 23 is read out to the control portion.

With the above, the series of operations of charge accumulation, a resetoperation, and charge transfer is completed.

Operation of the amplification transistor TR1 _(amp) and the selectiontransistor TR1 _(sel) after electrons are read out into the firstfloating diffusion layer FD₁ is the same as operation of conventionalamplification transistor and selection transistor. Further, for example,such a series of operations as charge accumulation, a reset operation,and charge transfer of the second imaging element and the third imagingelement is similar to a conventional series of operations of chargeaccumulation, a reset operation, and charge transfer.

In the embodiment 9, since what are generally called overflowingelectrons are sent out to the driving circuit through the chargedischarging electrode 26, leakage of electrons into the chargeaccumulation portion of an adjacent pixel can be suppressed andoccurrence of blooming can be suppressed. Consequently, the imagingperformance of the imaging element can be improved.

Although the present disclosure has been described on the basis of thepreferred embodiments, the present disclosure is not restricted to theembodiments. The structure and configuration, production conditions,production methods, and used materials of the solid-state image sensorsdescribed with reference to the embodiments are exemplary and can bechanged suitably. The imaging elements described in connection with theembodiments can be combined suitably.

In some cases, it is also possible to share the flowing diffusion layersFD₂, FD₃, 45C, and 46C as described hereinabove.

Further, as depicted in FIG. 36 that depicts a modification of thesolid-state image sensor described hereinabove, for example, inconnection with the embodiment 1, the solid-state image sensor can beconfigured such that light is incident from the side of the secondelectrode 22 and a shading layer 92 is formed on the light incidenceside rather near to the second electrode 22. It is to be noted that alsoit is possible to cause various wirings provided on the light incidenceside with respect to the light conversion portion to function as ashading layer.

It is to be noted that, although, in the example depicted in FIG. 36 ,the shading layer 92 is formed above the second electrode 22, that is,although the shading layer 92 is formed above the first electrode 21 onthe light incidence side rather near to the second electrode 22, theshading layer 92 may otherwise be arranged on a face of the secondelectrode 22 on the light incidence side as depicted in FIG. 37 .Further, in some cases, the shading layer 92 may be formed on the secondelectrode 22 as depicted in FIG. 38 .

Alternatively, it is also possible to adopt such a structure that lightis incident from the second electrode 22 side while light is notincident to the first electrode 21. In particular, as depicted in FIG.36 , the shading layer 92 is formed above on the first electrode 21 onthe light incidence side rather near to the second electrode 22.Alternatively, such a structure as depicted in FIG. 40 may be used inwhich an on-chip microlens 90 is provided above the charge accumulatingelectrode 24 and the second electrode 22 such that light incident to theon-chip microlens 90 is focused on the charge accumulating electrode 24and does not reach the first electrode 21. It is to be note that, in acase where the transfer controlling electrode 25 is provided asdescribed hereinabove in connection with the embodiment 11, it ispossible to adopt a form in which light is not incident to the firstelectrode 21 and the transfer controlling electrode 25, andparticularly, it is also possible to adopt a structure that the shadinglayer 92 is formed above the first electrode 21 and the transfercontrolling electrode 25 as depicted in FIG. 39 . Alternatively, it isalso possible to adopt a structure in which light incident to theon-chip microlens 90 does not reach the first electrode 21 or to thefirst electrode 21 and the transfer controlling electrode 25.

By adopting such configurations or structures as described above, or byproviding the shading layer 92 or designing the on-chip microlens 90such that light is incident only to a portion of the photoelectricconversion portion 23 positioned above the charge accumulating electrode24, a portion of the photoelectric conversion portion 23 that ispositioned above the first electrode 21 (or above the first electrode 21and the transfer controlling electrode 25) does not contribute tophotoelectric conversion. Therefore, all pixels can be reset all at oncewith a higher degree of accuracy, and a global shutter function can beimplemented more easily. In other words, in a driving method for asolid-state image sensor that includes a plurality of imaging elementhaving such configurations or structures as described above, thefollowing steps are repeated: discharging, in all imaging elements allat once, while charge is accumulated into the photoelectric conversionportion 23, charge in the first electrode 21 to the outside of thesystem; and then transferring, in all imaging elements all at once, thecharge accumulated in the photoelectric conversion portion 23 to thefirst electrode 21 and sequentially reading out, after completion of thetransfer, the charge transferred to the first electrode 21 in eachimaging element.

In such a driving method for a solid-state image sensor as describedabove, each imaging element is structured such that light incident fromthe second electrode side is not incident to the first electrode, and,in all imaging elements all at once, while charge is accumulated intothe photoelectric conversion portion, charge in the first electrode isdischarged to the outside of the system. Therefore, in all imagingelements all at once, resetting of the first electrode can be performedwith certainty. Thereafter, in all imaging elements, charge accumulatedin the photoelectric conversion portion is transferred to the firstelectrode, and after completion of the transfer, the charge transferredto the first electrode in the imaging elements is read out sequentially.Therefore, what is generally called global shutter function can beimplemented more easily.

Although, in the embodiments, electrons are signal charge and theconduction type of the photoelectric conversion portion formed on thesemiconductor substrate is the n type, the technology according to thepresent disclosure can be applied to a solid-state image sensor in whichpositive holes are signal charge. In this case, it is sufficient if eachsemiconductor region is formed by a semiconductor region of the reverseconduction type and it is sufficient if the conduction type of thephotoelectric conversion portion formed on the semiconductor substrateis the p type.

Further, while the embodiments are described taking a case in which thetechnology according to the present disclosure is applied to a CMOS typesolid-state image sensor in which unit pixels that detect signal chargeaccording to an incident light amount as a physical quantity arearranged in rows and columns as an example, application of thetechnology according to the present disclosure is not limited to a CMOStype solid-state image sensor, but the technology according to thepresent disclosure can also be applied to a CCD type solid-state imagesensor. In the latter case, signal charge is transferred in the verticaldirection by a vertical transfer register of the CCD type structure andtransferred in the horizontal direction by a horizontal transferregister and then amplified to output a pixel signal (image signal).Further, the solid-state image sensor is not limited to column typesolid-state image sensors in general in which pixels are formed in atwo-dimensional matrix and a column signal processing circuit isarranged for each pixel column. Further, in some cases, it is alsopossible to omit the selection transistor.

Further, the application of the solid-state image sensor of the presentdisclosure is not limited to the application of a solid-state imagesensor that detects and captures a distribution of an incident lightamount of visible light as an image, but the solid-state image sensor ofthe present disclosure can also be applied to a solid-state image sensorthat captures a distribution of an incident amount of infrared rays, Xrays, particles, or the like as an image. Further, in a wide sense, thesolid-state image sensor of the present disclosure can be applied tosolid-state image sensors (physical quantity distribution detectionapparatus) in general such as a fingerprint detection sensor thatdetects and captures a distribution of any other physical quantity suchas pressure or capacitance.

Further, the solid-state image sensor of the present disclosure is notlimited to a solid-state image sensor that scans unit pixels in animaging region in order in a unit of a row to read out a pixel signalfrom each unit pixel. The solid-state image sensor of the presentdisclosure can also be applied to a solid-state image sensor of the X-Yaddress type in which any pixel is selected in a unit of a pixel to readout a pixel signal in a unit of a pixel from the selected pixel. Thesolid-state image sensor may be formed as one chip or may be formed as amodule having an imaging function in which an imaging region and adriving circuit or an optical system are packaged collectively.

Further, the technology according to the present disclosure is notlimited to a solid-state image sensor but is also applicable to animaging apparatus. Here, the imaging apparatus signifies a camera systemsuch as a digital still camera or a video camera and electronicequipment having an imaging function such as a mobile phone. The imagesensor sometimes has a form of a module incorporated in electronicequipment, that is, the image sensor sometimes is formed as a cameramodule.

An example in which a solid-state image sensor 201 configured from thesolid-state image sensor of the present disclosure is used in electronicequipment (camera) 200 is depicted as a conceptual diagram in FIG. 41 .The electronic equipment 200 includes a solid-state image sensor 201, anoptical lens 210, a shutter device 211, a driving circuit 212, and asignal processing circuit 213. The optical lens 210 forms an image ofimage light (incident light) from an imaging target on an imaging planeof the solid-state image sensor 201. Consequently, signal charge isaccumulated for a fixed period of time into the solid-state image sensor201. The shutter device 211 controls the light irradiation period andthe light blocking period to the solid-state image sensor 201. Thedriving circuit 212 supplies a driving signal for controlling transferoperation and so forth of the solid-state image sensor 201 and shutteroperation of the shutter device 211. In response to a driving signal(timing signal) supplied from the driving circuit 212, signal transferof the solid-state image sensor 201 is performed. The signal processingcircuit 213 performs various signal processes. A video signal for whichthe signal processes have been performed is stored into a storage mediumsuch as a memory or is outputted to a monitor. In such electronicequipment 200 as described above, since refinement of the pixel size andimprovement of the transfer efficiency of the solid-state image sensor201 can be achieved, the electronic equipment 200 whose improvement inpixel characteristic is achieved can be obtained. The electronicequipment 200 to which the solid-state image sensor 201 can be appliedis not limited to a camera but can be applied to an imaging sensor suchas a camera module for mobile equipment such as a digital still cameraor a mobile phone.

In a case where P=2 and Q=2 are satisfied in the solid-state imagesensor of the embodiment 3 or the solid-state image sensor of theembodiment 4, a driving method described below can be adopted. In otherwords, as depicted in a schematic view of FIG. 42 , four imagingelements 11 _(2p+1,2q+1), 11 _(2p+1,2q+2), 11 _(2p+2,2q+1), and 11_(2p+2,2q+2) which configure one imaging element block (where p is 0 ora positive integer and q is 0 or a positive integer) are assumed. Here,the charge accumulating electrode 24 of the imaging element 11_(2p+1,2q+1) is connected to a (2q+1)th horizontal driving lineL_(2q+1). The charge accumulating electrode 24 of the imaging element 11_(2p+1,2q+2) is connected to a (2q+2)th horizontal driving lineL_(2q+2). The charge accumulating electrode 24 of the imaging element 11_(2p+2,2q+1) is connected to a (2q)th horizontal driving line L_(2q).The charge accumulating electrode 24 of the imaging element 11_(2p+2,2q+2) is connected to a (2q+3)th horizontal driving lineL_(2q+3).

By configuring the solid-state image sensor in such a manner asdescribed above, while usually four horizontal driving lines arerequired to drive charge accumulating electrodes in four imagingelements that configure one imaging element block, the number ofhorizontal driving lines can be reduced to two. Further, by suitablydriving the four horizontal driving lines L_(2q), L_(2q+1), L_(2q+2),and L_(2q+3), charge in the imaging elements 11 _(2p+1,2q+1), 11_(2p+1,2q+2), 11 _(2p+2,2q+1), and 11 _(2p+2,2q+2) can be read out.

The technology according to the present disclosure (present technology)can be applied to various products. For example, the technologyaccording to the present disclosure may be implemented as an apparatusthat is incorporated in any of various kinds of mobile bodies such as anautomobile, an electric automobile, a hybrid electric automobile, amotorcycle, a bicycle, a personal mobility, an airplane, a drone, aship, and a robot.

FIG. 44 is a block diagram depicting an example of schematicconfiguration of a vehicle control system as an example of a mobile bodycontrol system to which the technology according to an embodiment of thepresent disclosure can be applied.

The vehicle control system 12000 includes a plurality of electroniccontrol units connected to each other via a communication network 12001.In the example depicted in FIG. 44 , the vehicle control system 12000includes a driving system control unit 12010, a body system control unit12020, an outside-vehicle information detecting unit 12030, anin-vehicle information detecting unit 12040, and an integrated controlunit 12050. In addition, a microcomputer 12051, a sound/image outputsection 12052, and a vehicle-mounted network interface (I/F) 12053 areillustrated as a functional configuration of the integrated control unit12050.

The driving system control unit 12010 controls the operation of devicesrelated to the driving system of the vehicle in accordance with variouskinds of programs. For example, the driving system control unit 12010functions as a control device for a driving force generating device forgenerating the driving force of the vehicle, such as an internalcombustion engine, a driving motor, or the like, a driving forcetransmitting mechanism for transmitting the driving force to wheels, asteering mechanism for adjusting the steering angle of the vehicle, abraking device for generating the braking force of the vehicle, and thelike.

The body system control unit 12020 controls the operation of variouskinds of devices provided to a vehicle body in accordance with variouskinds of programs. For example, the body system control unit 12020functions as a control device for a keyless entry system, a smart keysystem, a power window device, or various kinds of lamps such as aheadlamp, a backup lamp, a brake lamp, a turn signal, a fog lamp, or thelike. In this case, radio waves transmitted from a mobile device as analternative to a key or signals of various kinds of switches can beinput to the body system control unit 12020. The body system controlunit 12020 receives these input radio waves or signals, and controls adoor lock device, the power window device, the lamps, or the like of thevehicle.

The outside-vehicle information detecting unit 12030 detects informationabout the outside of the vehicle including the vehicle control system12000. For example, the outside-vehicle information detecting unit 12030is connected with an imaging section 12031. The outside-vehicleinformation detecting unit 12030 makes the imaging section 12031 imagean image of the outside of the vehicle, and receives the imaged image.On the basis of the received image, the outside-vehicle informationdetecting unit 12030 may perform processing of detecting an object suchas a human, a vehicle, an obstacle, a sign, a character on a roadsurface, or the like, or processing of detecting a distance thereto.

The imaging section 12031 is an optical sensor that receives light, andwhich outputs an electric signal corresponding to a received lightamount of the light. The imaging section 12031 can output the electricsignal as an image, or can output the electric signal as informationabout a measured distance. In addition, the light received by theimaging section 12031 may be visible light, or may be invisible lightsuch as infrared rays or the like.

The in-vehicle information detecting unit 12040 detects informationabout the inside of the vehicle. The in-vehicle information detectingunit 12040 is, for example, connected with a driver state detectingsection 12041 that detects the state of a driver. The driver statedetecting section 12041, for example, includes a camera that images thedriver. On the basis of detection information input from the driverstate detecting section 12041, the in-vehicle information detecting unit12040 may calculate a degree of fatigue of the driver or a degree ofconcentration of the driver, or may determine whether the driver isdozing.

The microcomputer 12051 can calculate a control target value for thedriving force generating device, the steering mechanism, or the brakingdevice on the basis of the information about the inside or outside ofthe vehicle which information is obtained by the outside-vehicleinformation detecting unit 12030 or the in-vehicle information detectingunit 12040, and output a control command to the driving system controlunit 12010. For example, the microcomputer 12051 can perform cooperativecontrol intended to implement functions of an advanced driver assistancesystem (ADAS) which functions include collision avoidance or shockmitigation for the vehicle, following driving based on a followingdistance, vehicle speed maintaining driving, a warning of collision ofthe vehicle, a warning of deviation of the vehicle from a lane, or thelike.

In addition, the microcomputer 12051 can perform cooperative controlintended for automatic driving, which makes the vehicle to travelautonomously without depending on the operation of the driver, or thelike, by controlling the driving force generating device, the steeringmechanism, the braking device, or the like on the basis of theinformation about the outside or inside of the vehicle which informationis obtained by the outside-vehicle information detecting unit 12030 orthe in-vehicle information detecting unit 12040.

In addition, the microcomputer 12051 can output a control command to thebody system control unit 12020 on the basis of the information about theoutside of the vehicle which information is obtained by theoutside-vehicle information detecting unit 12030. For example, themicrocomputer 12051 can perform cooperative control intended to preventa glare by controlling the headlamp so as to change from a high beam toa low beam, for example, in accordance with the position of a precedingvehicle or an oncoming vehicle detected by the outside-vehicleinformation detecting unit 12030.

The sound/image output section 12052 transmits an output signal of atleast one of a sound and an image to an output device capable ofvisually or auditorily notifying information to an occupant of thevehicle or the outside of the vehicle. In the example of FIG. 44 , anaudio speaker 12061, a display section 12062, and an instrument panel12063 are illustrated as the output device. The display section 12062may, for example, include at least one of an on-board display and ahead-up display.

FIG. 45 is a diagram depicting an example of the installation positionof the imaging section 12031.

In FIG. 45 , the imaging section 12031 includes imaging sections 12101,12102, 12103, 12104, and 12105.

The imaging sections 12101, 12102, 12103, 12104, and 12105 are, forexample, disposed at positions on a front nose, sideview mirrors, a rearbumper, and a back door of the vehicle 12100 as well as a position on anupper portion of a windshield within the interior of the vehicle. Theimaging section 12101 provided to the front nose and the imaging section12105 provided to the upper portion of the windshield within theinterior of the vehicle obtain mainly an image of the front of thevehicle 12100. The imaging sections 12102 and 12103 provided to thesideview mirrors obtain mainly an image of the sides of the vehicle12100. The imaging section 12104 provided to the rear bumper or the backdoor obtains mainly an image of the rear of the vehicle 12100. Theimaging section 12105 provided to the upper portion of the windshieldwithin the interior of the vehicle is used mainly to detect a precedingvehicle, a pedestrian, an obstacle, a signal, a traffic sign, a lane, orthe like.

Incidentally, FIG. 45 depicts an example of photographing ranges of theimaging sections 12101 to 12104. An imaging range 12111 represents theimaging range of the imaging section 12101 provided to the front nose.Imaging ranges 12112 and 12113 respectively represent the imaging rangesof the imaging sections 12102 and 12103 provided to the sideviewmirrors. An imaging range 12114 represents the imaging range of theimaging section 12104 provided to the rear bumper or the back door. Abird's-eye image of the vehicle 12100 as viewed from above is obtainedby superimposing image data imaged by the imaging sections 12101 to12104, for example.

At least one of the imaging sections 12101 to 12104 may have a functionof obtaining distance information. For example, at least one of theimaging sections 12101 to 12104 may be a stereo camera constituted of aplurality of imaging elements, or may be an imaging element havingpixels for phase difference detection.

For example, the microcomputer 12051 can determine a distance to eachthree-dimensional object within the imaging ranges 12111 to 12114 and atemporal change in the distance (relative speed with respect to thevehicle 12100) on the basis of the distance information obtained fromthe imaging sections 12101 to 12104, and thereby extract, as a precedingvehicle, a nearest three-dimensional object in particular that ispresent on a traveling path of the vehicle 12100 and which travels insubstantially the same direction as the vehicle 12100 at a predeterminedspeed (for example, equal to or more than 0 km/hour). Further, themicrocomputer 12051 can set a following distance to be maintained infront of a preceding vehicle in advance, and perform automatic brakecontrol (including following stop control), automatic accelerationcontrol (including following start control), or the like. It is thuspossible to perform cooperative control intended for automatic drivingthat makes the vehicle travel autonomously without depending on theoperation of the driver or the like.

For example, the microcomputer 12051 can classify three-dimensionalobject data on three-dimensional objects into three-dimensional objectdata of a two-wheeled vehicle, a standard-sized vehicle, a large-sizedvehicle, a pedestrian, a utility pole, and other three-dimensionalobjects on the basis of the distance information obtained from theimaging sections 12101 to 12104, extract the classifiedthree-dimensional object data, and use the extracted three-dimensionalobject data for automatic avoidance of an obstacle. For example, themicrocomputer 12051 identifies obstacles around the vehicle 12100 asobstacles that the driver of the vehicle 12100 can recognize visuallyand obstacles that are difficult for the driver of the vehicle 12100 torecognize visually. Then, the microcomputer 12051 determines a collisionrisk indicating a risk of collision with each obstacle. In a situationin which the collision risk is equal to or higher than a set value andthere is thus a possibility of collision, the microcomputer 12051outputs a warning to the driver via the audio speaker 12061 or thedisplay section 12062, and performs forced deceleration or avoidancesteering via the driving system control unit 12010. The microcomputer12051 can thereby assist in driving to avoid collision.

At least one of the imaging sections 12101 to 12104 may be an infraredcamera that detects infrared rays. The microcomputer 12051 can, forexample, recognize a pedestrian by determining whether or not there is apedestrian in imaged images of the imaging sections 12101 to 12104. Suchrecognition of a pedestrian is, for example, performed by a procedure ofextracting characteristic points in the imaged images of the imagingsections 12101 to 12104 as infrared cameras and a procedure ofdetermining whether or not it is the pedestrian by performing patternmatching processing on a series of characteristic points representingthe contour of the object. When the microcomputer 12051 determines thatthere is a pedestrian in the imaged images of the imaging sections 12101to 12104, and thus recognizes the pedestrian, the sound/image outputsection 12052 controls the display section 12062 so that a squarecontour line for emphasis is displayed so as to be superimposed on therecognized pedestrian. The sound/image output section 12052 may alsocontrol the display section 12062 so that an icon or the likerepresenting the pedestrian is displayed at a desired position.

Further, for example, the technology according to the present disclosuremay be applied to an endoscopic surgery system.

FIG. 46 is a view depicting an example of a schematic configuration ofan endoscopic surgery system to which the technology according to anembodiment of the present disclosure (present technology) can beapplied.

In FIG. 46 , a state is illustrated in which a surgeon (medical doctor)11131 is using an endoscopic surgery system 11000 to perform surgery fora patient 11132 on a patient bed 11133. As depicted, the endoscopicsurgery system 11000 includes an endoscope 11100, other surgical tools11110 such as a pneumoperitoneum tube 11111 and an energy device 11112,a supporting arm apparatus 11120 which supports the endoscope 11100thereon, and a cart 11200 on which various apparatus for endoscopicsurgery are mounted.

The endoscope 11100 includes a lens barrel 11101 having a region of apredetermined length from a distal end thereof to be inserted into abody cavity of the patient 11132, and a camera head 11102 connected to aproximal end of the lens barrel 11101. In the example depicted, theendoscope 11100 is depicted which includes as a rigid endoscope havingthe lens barrel 11101 of the hard type. However, the endoscope 11100 mayotherwise be included as a flexible endoscope having the lens barrel11101 of the flexible type.

The lens barrel 11101 has, at a distal end thereof, an opening in whichan objective lens is fitted. A light source apparatus 11203 is connectedto the endoscope 11100 such that light generated by the light sourceapparatus 11203 is introduced to a distal end of the lens barrel 11101by a light guide extending in the inside of the lens barrel 11101 and isirradiated toward an observation target in a body cavity of the patient11132 through the objective lens. It is to be noted that the endoscope11100 may be a forward-viewing endoscope or may be an oblique-viewingendoscope or a side-viewing endoscope.

An optical system and an image pickup element are provided in the insideof the camera head 11102 such that reflected light (observation light)from the observation target is condensed on the image pickup element bythe optical system. The observation light is photo-electricallyconverted by the image pickup element to generate an electric signalcorresponding to the observation light, namely, an image signalcorresponding to an observation image. The image signal is transmittedas RAW data to a CCU 11201.

The CCU 11201 includes a central processing unit (CPU), a graphicsprocessing unit (GPU) or the like and integrally controls operation ofthe endoscope 11100 and a display apparatus 11202. Further, the CCU11201 receives an image signal from the camera head 11102 and performs,for the image signal, various image processes for displaying an imagebased on the image signal such as, for example, a development process(demosaic process).

The display apparatus 11202 displays thereon an image based on an imagesignal, for which the image processes have been performed by the CCU11201, under the control of the CCU 11201.

The light source apparatus 11203 includes a light source such as, forexample, a light emitting diode (LED) and supplies irradiation lightupon imaging of a surgical region to the endoscope 11100.

An inputting apparatus 11204 is an input interface for the endoscopicsurgery system 11000. A user can perform inputting of various kinds ofinformation or instruction inputting to the endoscopic surgery system11000 through the inputting apparatus 11204. For example, the user wouldinput an instruction or a like to change an image pickup condition (typeof irradiation light, magnification, focal distance or the like) by theendoscope 11100.

A treatment tool controlling apparatus 11205 controls driving of theenergy device 11112 for cautery or incision of a tissue, sealing of ablood vessel or the like. A pneumoperitoneum apparatus 11206 feeds gasinto a body cavity of the patient 11132 through the pneumoperitoneumtube 11111 to inflate the body cavity in order to secure the field ofview of the endoscope 11100 and secure the working space for thesurgeon. A recorder 11207 is an apparatus capable of recording variouskinds of information relating to surgery. A printer 11208 is anapparatus capable of printing various kinds of information relating tosurgery in various forms such as a text, an image or a graph.

It is to be noted that the light source apparatus 11203 which suppliesirradiation light when a surgical region is to be imaged to theendoscope 11100 may include a white light source which includes, forexample, an LED, a laser light source or a combination of them. Where awhite light source includes a combination of red, green, and blue (RGB)laser light sources, since the output intensity and the output timingcan be controlled with a high degree of accuracy for each color (eachwavelength), adjustment of the white balance of a picked up image can beperformed by the light source apparatus 11203. Further, in this case, iflaser beams from the respective RGB laser light sources are irradiatedtime-divisionally on an observation target and driving of the imagepickup elements of the camera head 11102 are controlled in synchronismwith the irradiation timings. Then images individually corresponding tothe R, G and B colors can be also picked up time-divisionally. Accordingto this method, a color image can be obtained even if color filters arenot provided for the image pickup element.

Further, the light source apparatus 11203 may be controlled such thatthe intensity of light to be outputted is changed for each predeterminedtime. By controlling driving of the image pickup element of the camerahead 11102 in synchronism with the timing of the change of the intensityof light to acquire images time-divisionally and synthesizing theimages, an image of a high dynamic range free from underexposed blockedup shadows and overexposed highlights can be created.

Further, the light source apparatus 11203 may be configured to supplylight of a predetermined wavelength band ready for special lightobservation. In special light observation, for example, by utilizing thewavelength dependency of absorption of light in a body tissue toirradiate light of a narrow band in comparison with irradiation lightupon ordinary observation (namely, white light), narrow band observation(narrow band imaging) of imaging a predetermined tissue such as a bloodvessel of a superficial portion of the mucous membrane or the like in ahigh contrast is performed. Alternatively, in special light observation,fluorescent observation for obtaining an image from fluorescent lightgenerated by irradiation of excitation light may be performed. Influorescent observation, it is possible to perform observation offluorescent light from a body tissue by irradiating excitation light onthe body tissue (autofluorescence observation) or to obtain afluorescent light image by locally injecting a reagent such asindocyanine green (ICG) into a body tissue and irradiating excitationlight corresponding to a fluorescent light wavelength of the reagentupon the body tissue. The light source apparatus 11203 can be configuredto supply such narrow-band light and/or excitation light suitable forspecial light observation as described above.

FIG. 47 is a block diagram depicting an example of a functionalconfiguration of the camera head 11102 and the CCU 11201 depicted inFIG. 46 .

The camera head 11102 includes a lens unit 11401, an image pickup unit11402, a driving unit 11403, a communication unit 11404 and a camerahead controlling unit 11405. The CCU 11201 includes a communication unit11411, an image processing unit 11412 and a control unit 11413. Thecamera head 11102 and the CCU 11201 are connected for communication toeach other by a transmission cable 11400.

The lens unit 11401 is an optical system, provided at a connectinglocation to the lens barrel 11101. Observation light taken in from adistal end of the lens barrel 11101 is guided to the camera head 11102and introduced into the lens unit 11401. The lens unit 11401 includes acombination of a plurality of lenses including a zoom lens and afocusing lens.

The number of image pickup elements which is included by the imagepickup unit 11402 may be one (single-plate type) or a plural number(multi-plate type). Where the image pickup unit 11402 is configured asthat of the multi-plate type, for example, image signals correspondingto respective R, G and B are generated by the image pickup elements, andthe image signals may be synthesized to obtain a color image. The imagepickup unit 11402 may also be configured so as to have a pair of imagepickup elements for acquiring respective image signals for the right eyeand the left eye ready for three dimensional (3D) display. If 3D displayis performed, then the depth of a living body tissue in a surgicalregion can be comprehended more accurately by the surgeon 11131. It isto be noted that, where the image pickup unit 11402 is configured asthat of stereoscopic type, a plurality of systems of lens units 11401are provided corresponding to the individual image pickup elements.

Further, the image pickup unit 11402 may not necessarily be provided onthe camera head 11102. For example, the image pickup unit 11402 may beprovided immediately behind the objective lens in the inside of the lensbarrel 11101.

The driving unit 11403 includes an actuator and moves the zoom lens andthe focusing lens of the lens unit 11401 by a predetermined distancealong an optical axis under the control of the camera head controllingunit 11405. Consequently, the magnification and the focal point of apicked up image by the image pickup unit 11402 can be adjusted suitably.

The communication unit 11404 includes a communication apparatus fortransmitting and receiving various kinds of information to and from theCCU 11201. The communication unit 11404 transmits an image signalacquired from the image pickup unit 11402 as RAW data to the CCU 11201through the transmission cable 11400.

In addition, the communication unit 11404 receives a control signal forcontrolling driving of the camera head 11102 from the CCU 11201 andsupplies the control signal to the camera head controlling unit 11405.The control signal includes information relating to image pickupconditions such as, for example, information that a frame rate of apicked up image is designated, information that an exposure value uponimage picking up is designated and/or information that a magnificationand a focal point of a picked up image are designated.

It is to be noted that the image pickup conditions such as the framerate, exposure value, magnification or focal point may be designated bythe user or may be set automatically by the control unit 11413 of theCCU 11201 on the basis of an acquired image signal. In the latter case,an auto exposure (AE) function, an auto focus (AF) function and an autowhite balance (AWB) function are incorporated in the endoscope 11100.

The camera head controlling unit 11405 controls driving of the camerahead 11102 on the basis of a control signal from the CCU 11201 receivedthrough the communication unit 11404.

The communication unit 11411 includes a communication apparatus fortransmitting and receiving various kinds of information to and from thecamera head 11102. The communication unit 11411 receives an image signaltransmitted thereto from the camera head 11102 through the transmissioncable 11400.

Further, the communication unit 11411 transmits a control signal forcontrolling driving of the camera head 11102 to the camera head 11102.The image signal and the control signal can be transmitted by electricalcommunication, optical communication or the like.

The image processing unit 11412 performs various image processes for animage signal in the form of RAW data transmitted thereto from the camerahead 11102.

The control unit 11413 performs various kinds of control relating toimage picking up of a surgical region or the like by the endoscope 11100and display of a picked up image obtained by image picking up of thesurgical region or the like. For example, the control unit 11413 createsa control signal for controlling driving of the camera head 11102.

Further, the control unit 11413 controls, on the basis of an imagesignal for which image processes have been performed by the imageprocessing unit 11412, the display apparatus 11202 to display a pickedup image in which the surgical region or the like is imaged. Thereupon,the control unit 11413 may recognize various objects in the picked upimage using various image recognition technologies. For example, thecontrol unit 11413 can recognize a surgical tool such as forceps, aparticular living body region, bleeding, mist when the energy device11112 is used and so forth by detecting the shape, color and so forth ofedges of objects included in a picked up image. The control unit 11413may cause, when it controls the display apparatus 11202 to display apicked up image, various kinds of surgery supporting information to bedisplayed in an overlapping manner with an image of the surgical regionusing a result of the recognition. Where surgery supporting informationis displayed in an overlapping manner and presented to the surgeon11131, the burden on the surgeon 11131 can be reduced and the surgeon11131 can proceed with the surgery with certainty.

The transmission cable 11400 which connects the camera head 11102 andthe CCU 11201 to each other is an electric signal cable ready forcommunication of an electric signal, an optical fiber ready for opticalcommunication or a composite cable ready for both of electrical andoptical communications.

Here, while, in the example depicted, communication is performed bywired communication using the transmission cable 11400, thecommunication between the camera head 11102 and the CCU 11201 may beperformed by wireless communication.

It is to be noted here that, although an endoscopic surgery system isdescribed as an example, the technology according to the presentdisclosure may be applied further, for example, to a microscopic surgerysystem and so forth.

It is to be noted that the present disclosure can take suchconfigurations as described below.

[A01]

<<Solid-State Image Sensor>>

A solid-state image sensor including:

a plurality of imaging element blocks each configured from a pluralityof imaging elements, in which

each of the imaging elements includes

-   -   a first electrode,    -   a charge accumulating electrode arranged in a spaced relation        from the first electrode,    -   a photoelectric conversion portion contacting with the first        electrode and formed above the charge accumulating electrode        with an insulating layer interposed therebetween, and    -   a second electrode formed on the photoelectric conversion        portion,

the first electrode and the charge accumulating electrode are providedon an interlayer insulating layer, and

the first electrode is connected to a connection portion provided in theinterlayer insulating layer.

[A02]

The solid-state image sensor according to [A01], in which the imagingelement block is configured from P×Q (where, P≥2 and Q≥1) imagingelements including P imaging elements along a first direction and Qimaging elements along a second direction different from the firstdirection.

[A03]

<<Solid-State Image Sensor of the First Configuration>>

The solid-state image sensor according to [A02], in which

P=2 and Q=1 are satisfied, and

first electrodes individually configuring two imaging elements along thefirst direction are connected to the connection portion provided in theinterlayer insulating layer.

[A04]

The solid-state image sensor according to [A03], in which the imagingelement block is surrounded by a continuous isolation electrode.

[A05]

The solid-state image sensor according to [A04], in which a continuoussecond isolation electrode extending along the second direction from theisolation electrode is provided between the two imaging elements alongthe first direction.

[A06]

The solid-state image sensor according to [A03], in which a secondisolation electrode extending along the second direction is providedbetween the two imaging elements along the first direction.

[A07]

<<Solid-State Image Sensor of the Second Configuration>>

The solid-state image sensor according to [A02], in which

P=2 is satisfied, and Q is a natural number equal to or greater than 2,and

first electrodes individually configuring two imaging elements along thefirst direction are connected to the connection portion provided in theinterlayer insulating layer.

[A08]

The solid-state image sensor according to [A07], in which the imagingelement block is surrounded by a continuous isolation electrode.

[A09]

The solid-state image sensor according to [A08], in which a continuoussecond isolation electrode extending along the second direction from theisolation electrode is provided between the two imaging elements alongthe first direction.

[A10]

The solid-state image sensor according to [A07], in which a secondisolation electrode extending along the second direction is providedbetween the two imaging elements along the first direction.

[A11]

<<Solid-State Image Sensor of the 3Ath Configuration>>

The solid-state image sensor according to [A02], in which

P=2 and Q=2 are satisfied,

a first electrode configuring two imaging elements along the seconddirection is shared, and

the shared first electrode is connected to the connection portionprovided in the interlayer insulating layer.

[A12]

<<Solid-State Image Sensor of the 3Ath Configuration>>

The solid-state image sensor according to [A02], in which

P=2 and Q=2 are satisfied,

a first electrode configuring two imaging elements along the firstdirection is shared, and

the shared first electrode is connected to the connection portionprovided in the interlayer insulating layer.

[A13]

The solid-state image sensor according to [A11] or [A12], in which theimaging element block is surrounded by a continuous isolation electrode.

[A14]

The solid-state image sensor according to [A13], in which a continuoussecond isolation electrode extending along the second direction from theisolation electrode is provided between the two imaging elements alongthe first direction.

[A15]

The solid-state image sensor according to [A11], in which a secondisolation electrode extending along the second direction is providedbetween two imaging elements along the first direction.

[A16]

The solid-state image sensor according to any one of [A01] to [A15], inwhich the imaging elements are arranged line-symmetrically with respectto a boundary line extending in a second direction between the imagingelements configuring the imaging element block.

[A17]

The solid-state image sensor according to any one of [A04] to [A16], inwhich a potential of the isolation electrode has a fixed value V_(ES).

REFERENCE SIGNS LIST

10 . . . Imaging element block, 21 . . . First electrode, 22 . . .Second electrode, 23 . . . Photoelectric conversion portion, 23 _(up) .. . Upper layer photoelectric conversion layer, 23 _(DN) . . . Lowerlayer semiconductor layer, 24 . . . Charge accumulating electrode, 25 .. . Transfer controlling electrode (charge transfer electrode), 25A, 26A. . . Connecting portion, 26 . . . Charge discharging electrode, 27 . .. Isolation electrode (lower isolation electrode), 27′ . . . Upperisolation electrode, 28 . . . First isolation electrode (lower firstisolation electrode), 29 . . . Second isolation electrode (upper secondisolation electrode), 41 . . . n-type semiconductor region (secondphotoelectric conversion portion) configuring second imaging element, 43. . . n-type semiconductor region (third photoelectric conversionportion) configuring third imaging element, 42, 44, 73 . . . p⁺ layer,FD₁, FD₂, FD₃, 45C, 46C . . . Floating diffusion region, TR1 _(amp) . .. Amplification transistor, TR1 _(rst) . . . Reset transistor, TR1_(sel) . . . Selection transistor, 51 . . . Gate portion of resettransistor TR1 _(rst), 51A . . . Channel formation region of resettransistor TR1 _(rst), 51B, 51C . . . Source/drain region of resettransistor TR1 _(rst), 52 . . . Gate portion of amplification transistorTR1 _(amp), 52A . . . Channel formation region of amplificationtransistor TR1 _(amp), 52B, 52C . . . Source/drain region ofamplification transistor TR1 _(amp), 53 . . . Gate portion of selectiontransistor TR1 _(sel), 53A . . . Channel formation region of selectiontransistor TR1 _(sel), 53B, 53C . . . Source/drain region of selectiontransistor TR1 _(sel), TR2 _(trs) . . . Transfer transistor, 45 . . .Gate portion of transfer transistor, TR2 _(rst) . . . Reset transistor,TR2 _(amp) . . . Amplification transistor, TR2 _(sel) . . . Selectiontransistor, TR3 _(trs) . . . Transfer transistor, 46 . . . Gate portionof transfer transistor, TR3 _(rst) . . . . Reset transistor, TR3 _(amp). . . Amplification transistor, TR3 _(sel) . . . Selection transistor,V_(DD) . . . Power supply, RST₁, RST₂, RST₃ . . . Reset line, SEL₁,SEL₂, SEL₃ . . . Selection line, 117, VSL₁, VSL₂, VSL₃ . . . Signalline, TG₂, TG₃ . . . Transfer gate line, V_(OA), V_(OB)/V_(OT)/V_(OU) .. . Wiring, 61 . . . Contact hole portion, 62 . . . Wiring layer, 63 . .. Connection portion, 64 . . . Wiring layer, 65 . . . Connection hole,66 . . . Pad portion, 67, 68 . . . Connecting portion, 70 . . .Semiconductor substrate, 70A . . . First face (front face) ofsemiconductor substrate, 70B . . . Second face (rear face) ofsemiconductor substrate, 71 . . . Element isolation region, 72 . . .Insulating material film, 74 . . . HfO₂ film, 75 . . . Insulating film,76 . . . Interlayer insulating film, 81 . . . Interlayer insulatinglayer, 82 . . . Insulating layer, 83 . . . Protective layer, 84 . . .Opening, 85 . . . Second opening, 90 . . . On-chip microlens, 91 . . .Various imaging element components positioned below interlayerinsulating layer, 92 . . . Shading layer, 100 . . . Solid-state imagesensor, 101 . . . Stacked type imaging element, 111 . . . Imagingregion, 112 . . . Vertical driving circuit, 113 . . . Column signalprocessing circuit, 114 . . . Horizontal driving circuit, 115 . . .Outputting circuit, 116 . . . Driving controlling circuit, 118 . . .Horizontal signal line, 200 . . . Electronic equipment (camera), 201 . .. Solid-state image sensor, 210 . . . Optical lens, 211 . . . Shutterdevice, 212 . . . Driving circuit, 213 . . . Signal processing circuit

What is claimed is:
 1. A solid-state image sensor, comprising: aplurality of imaging element blocks each configured from a plurality ofimaging elements, wherein each of the imaging elements includes: a firstelectrode; a charge accumulating electrode arranged in a spaced relationfrom the first electrode; a photoelectric conversion portion contactingthe first electrode and formed above the charge accumulating electrode,wherein an insulating layer is interposed between the photoelectricconversion portion and the charge accumulating electrode; and a secondelectrode formed on the photoelectric conversion portion, wherein thefirst electrode and the charge accumulating electrode are provided on aninterlayer insulating layer, wherein at least one of the imaging elementblocks is configured from P×Q (where, P≥2 and Q≥1) imaging elementsincluding P imaging elements along a first direction and Q imagingelements along a second direction different from the first direction,and wherein the first electrode of a first one of the imaging elementsand the first electrode of a second one of the imaging elements areconnected to a common connection portion provided in the interlayerinsulating layer.
 2. The solid-state image sensor according to claim 1,wherein P=2 and Q=1 are satisfied.
 3. The solid-state image sensoraccording to claim 2, wherein the at least one imaging element block issurrounded by a continuous first isolation electrode.
 4. The solid-stateimage sensor according to claim 3, wherein a continuous second isolationelectrode extending along the second direction from the first isolationelectrode is provided between the first one of the imaging elements andthe second one of the imaging elements along the first direction.
 5. Thesolid-state image sensor according to claim 2, wherein an isolationelectrode extending along the second direction is provided between thefirst one of the imaging elements and the second one of the imagingelements along the first direction.
 6. The solid-state image sensoraccording to claim 1, wherein P=2 is satisfied, and Q is a naturalnumber equal to or greater than
 2. 7. The solid-state image sensoraccording to claim 6, wherein the at least one imaging element block issurrounded by a continuous first isolation electrode.
 8. The solid-stateimage sensor according to claim 7, wherein a continuous second isolationelectrode extending along the second direction from the first isolationelectrode is provided between the first one of the imaging elements andthe second one of the imaging elements along the first direction.
 9. Thesolid-state image sensor according to claim 6, wherein an isolationelectrode extending along the second direction is provided between thefirst one of the imaging elements and the second one of the imagingelements along the first direction.
 10. The solid-state image sensoraccording to claim 1, wherein P=2 and Q=2 are satisfied, and wherein thefirst one of the imaging elements and the second one of the imagingelements are adjacent to one another along the second direction.
 11. Thesolid-state image sensor according to claim 1, wherein P=2 and Q=2 aresatisfied, and wherein the first one of the imaging elements and thesecond one of the imaging elements are adjacent to one another along thefirst direction.
 12. The solid-state image sensor according to claim 10,wherein the at least one imaging element block is surrounded by acontinuous first isolation electrode.
 13. The solid-state image sensoraccording to claim 12, wherein a continuous second isolation electrodeextending along the second direction from the first isolation electrodeis provided between the first one of the imaging elements and the secondone of the imaging elements along the first direction.
 14. Thesolid-state image sensor according to claim 10, wherein an isolationelectrode extending along the second direction is provided between twoimaging elements along the first direction.
 15. The solid-state imagesensor according to claim 1, wherein the first one of the imagingelements and the second one of the imaging elements are arrangedline-symmetrically with respect to a boundary line extending in thesecond direction between the first one of the imaging elements and thesecond one of the imaging elements configuring the at least one imagingelement block.
 16. The solid-state image sensor according to claim 3,wherein a potential of the first isolation electrode has a fixed valueV_(ES).
 17. The solid-state image sensor according to claim 11, whereinthe imaging element block is surrounded by a continuous first isolationelectrode.